[تم الحل] I can't find translation string

Background of the issue:
I'm trying to translate the link of a button on my site الرابط المخفي. The text is already translated, but I can't find the string for its link.

Symptoms:
I can't find the translation string for the button's link.

Questions:
The button is "BOOK NOW" tekst in EN. In PL it's "SPRAWDŹ CENY". i REALLY CAN'T FIND IT ANYWHERE. I tryed to look for it by "Look for strings while pages are rendered" but it doesn't work. I tryed to find it in string - but I can't. This button is in header area. You already helped me with similar problem recently, giving code to Settings - Custom XML Configuration. I would do the same if I could only find this string. I gave you recently access to my wordpress website.