How do you add or 'inject' a php function just after the text of a WP Menu item link?

Hello Support,

I hope you are all doing well today!

I would like to insert dynamic (echo some content) on an specific WP Menu item just after the menu item link (text).

This is just an example:
'name of menu' = Primary
'name or id of menu item' = New Posts or id=22
So on the Primary Menu and menu item "New Posts" I would like to put "The number of new posts" (just as an example)...

So I would basically like to 'echo' whatever content I'm looking to add after the text link of the menu item.

(I already have the function I would like to echo or insert after the menu item but explaining what it is shouldn't be necessary and it would take me too long to explain what it is and why I want it where I want it)

I have read lots of posts and found solutions that might work but ultimately I'm still learning php and at this point my brain is mush

I'm sure this question is outside of your standard support so I don't expect much, just hoping someone here knows exactly what I'm trying to do and can help me write the function to echo the results of (the other function)