QGA can consume geodata from many different sources, here's what's needed to use a TMS a background map in QGA.

Sense Map chart

Start with specifying the source. In this case the source is a TMS from ArcGIS Online: World_Topo_Map.

1. The TMS service is specified as a url with parameters for X, Y as Z, which specifies the position of the map image and the scale level. At ArcGIS Online the start tile is defined as: https://services.arcgisonline.com/arcgis/rest/services/World_Topo_Map/MapServer/tile/0/0/0 with z, y, x‌ as the order of the last parameters.
2. Exchange the last part of the parameters and format as a string, this is the Tile Service URL:
   
   ='http://server.arcgisonline.com/arcgis/rest/services/World_Topo_Map/MapServer/tile/${z}/${y}/${x}'
   
   
3. Create a map and add a Background layer
4. For the Background layer specify the URL.
5. Don't forget to include the copyright text in the attribution:
   
   Sources: Esri, HERE, DeLorme, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), swisstopo, MapmyIndia, © OpenStreetMap contributors, and the GIS User Community

Old QGA Map extensions

Start with specifying the source. In this case the source is a TMS from ArcGIS Online: World_Topo_Map.

1. The TMS service is specified as a url with parameters for X, Y as Z, which specifies the position of the map image and the scale level. At ArcGIS Online the start tile is defined as: https://services.arcgisonline.com/arcgis/rest/services/World_Topo_Map/MapServer/tile/0/0/0 with z, y, x‌ as the order of the last parameters.
2. Exchange the last part of the parameters and format as a string, this is the Tile Service URL:
   
   ='http://server.arcgisonline.com/arcgis/rest/services/World_Topo_Map/MapServer/tile/{z}/{y}/{x}'
   
   
3. Create a map view and a geodata layer
4. For the geodata layer specify the Tile Service URL and Source format: TMS and Tile Size: 256.
5. Don't forget to include the copyright text some where in the app, in this case the attribution should be:
   
   Sources: Esri, HERE, DeLorme, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), swisstopo, MapmyIndia, © OpenStreetMap contributors, and the GIS User Community

See also the two attachments, example apps for Qlik Sense and QlikView.¨

Authentication in ArcGIS

Special note regarding Authentication in ArcGIS (Thanks to ssamuels for the solution)

The authentication when working with secured map services from ESRI can be solved by setting up a REST connection in the loadscript to retrieve a new access token from the REST API of ArcGIS Online. This is done by sending a GenerateToken request to the URL "https://www.arcgis.com/sharing/generateToken?parameters".  The REST call must be a POST request over https and takes the following parameters:

username - Username of the user who wishes to get a token.

password - Password of user who wishes to get a token.

referer - The base URL of the web application that will invoke the services

expiration - The token expiration time in minutes (default value for this parameter is 60 minutes)

f - The response format. The value for this parameter must be "json".

The resulting access token is stored in the data model and can be used as a text variable to append to the location service url in the GeoAnalytics extension.

Connecting map chart with an on premise Qlik GeoAnalytics Server

From Qlik Sense April 2018, the built-in Map chart can be used with GeoAnalytics Server in an on-premise solution. For this GeoAnalytics Data Package 18.04 or newer is needed.

First, install the data package according the guide including the optional step named "Enable support for Qlik Sense Map" or similar.

Then go to your Qlik Sense installation and point the Sense map to the server by editing the file mapconf.json in C:\Program Files\Qlik\Sense\Client\assets (or similar) and set the URL to the server in the serverUrl property and the key you have chosen during data package installation for Sense map users in serverKey.

Example:
{
"serverUrl":"https://mysite.com",
"serverKey":"abcdefg"
}

Note that every time Qlik Sense is upgraded this file will be overwritten, so it will need to be edited again.

Custom default map background

For all new map charts per site. Edit Qlik\Sense\Client\assets\mapconf.json

Set alternative basemap:
        "defaultMap":"pale_mercator" (list of of possible values below)
Set any TMS:
         "defaultMap":"http://tile.openstreetmap.org/${z}/${x}/${y}.png"
Set attribution:
        "defaultAttribution":"copyright me"