You can't put a straight vertical line directly in Qlik Sense, you'd have to use a workaround with your data on it.
As an example, using the code bellow:
load * inline
max(B) as maxValue
left join (data)
Today() as A,
maxValue as C
drop table test;
Will get the reference line based on today's date and gets the max value from your dataset so that you can create a combo chart, having the lines as you have on your images, and an additional expression with a bar, that would be your reference line, giving the following result.
Adding more data to it, you'll get something like:
Hope it helps.
Attached is the sample QVF file aslo.
sample.qvf 191.5 K