Hello,
Use admin strings translator to add admin strings and translate them https://gyazo.com/a3aa2c782ccd3755100350fdd8c1af17
But I see that you have js error in console https://gyazo.com/1002fa492d3bc168a5ad574540a98784
So, contact WPML plugin support to get help with that error. After that you’ll be able to add strings to string translator
Regards