www.makemkv.com

Hello.
I've got today new Bluray player BP55EB40 SVC CODE: EB52

Manufacture date: 2025 March



Which firmware I have to upload to read UHD disc ?

I'm not an expert on this topic, but I think that drive is essentially a BP50NB40. https://forum.makemkv.com/forum/viewtopic.php?p=183019#p183019

You should be able to follow the Ultimate UHD Drives Flashing Guide.