quick question can I as a non-jewish person say Baruch Dayan Emet? (tw: antisemitism – mention?)

I just found out that a prominent holocaust survivor in my country who has done a lot of work for awareness, knowledge, understanding, support has died, and wanted to make a little post on social media about him. He spoke at my school years ago and I really appreciated that and I am worried about what will happen when the last survivors are gone.

Is it okay for me to say Baruch Dayan Emet in that post about him? Is there any other way to respectfully honor him? We usually say Rest in peace in my country but google says it’s a very christian term?

Thank you and take care <3

edit: not the last survivor, I misremembered, but still a prominent and important person. Sorry!