Format “Modified Date” like “Article Date”

My website: http://www.prüfungsfragen.de
I use the demo-theme: Royal Pub
I am a beginner.

1) Show “Modified Date” in posts
I would like to show the “Modified Date” on my posts. Therefore I activated “Show Modified Date” in the theme panel as shown here: https://prnt.sc/u93x1t
What else do I need to adjust, that the “Modified Date” will be displayed?

2) Show “Modified Date” in the same size and format as the “Article Date”
Alternatively I tried to add the “Modified Date” by inserting the Block “Single Post Modified Date” as shown here: https://prnt.sc/u93yjb

Could you give me please detailed instructions, how I can format the “Modified Date”, that the “Modified Date” will be shown in the same font, size and in the same row as the “Article Date”?

My website: http://www.prüfungsfragen.de
I use the demo-theme: Royal Pub
I am a beginner.

Thanks for your fast response.

I added the “Modified Date” by inserting the Block “Single Post Modified Date” as shown here: https://prnt.sc/u93yjb

I already tried to format the “Modified Date” like the “Article Date”. Here I show you both setting options in one screenshot (please scroll down the screenshot): https://prnt.sc/ud6dzb

I noticed that for instance that I cannot change the font-size of the “Single Post Modified Date”.

Could you give me please detailed instructions, how I can format the “Modified Date”, that the “Modified Date” will be shown in the same font, size and in the same row as the “Article Date”?

Thank you very much in advance.

Yes I did. This field was not active. I tried to change the font size there, but it was not possible.