How to translate the Button in the repeater part with WPML

Hi

How I can translate the button I have (or text) for the add / remove in the repeater? I am using WPML.

Also a question, if I like to have a unique number, for example on this page:

https://wp.member-diving.com/en/book-now-and-enquiry/

I have “Participant” and like to have there a number like #1 for participant 1, #2 for participant 2 etc, is this possible?

Regards,

Simon