Hi @Saudi.abdelsayed and welcome to our community!
Not sure if this answers your request 
but there is a number of institutions that we list here to verify our translators, these institution offer particular assessment tests and offer memberships and certificates 
On the other hand, what we offer here for our volunteers can be a good opportunity to build up their translation skills, enrich their CV/resume by working with an international non-profit, learn more about humanitarian translation and humanitarian response 
If you are interested in claiming tasks with us, kindly add the language pairs you can work on to your profile. After that, you ca refer to our Translator’s Manual to learn more about our workflow 
You can also follow these instructions to sign up to receive email notifications when tasks are available in your language pairs 
I hope this helps!