There is a way to join the unreal game by browser?
When developing for Webbrowsers with UE, you need to use UE 4.23. Newer versions of Unreal Engine (including UE 5) do NOT officially support web browsers and the unofficial community support for does not seem to be working properly (at least several Photon users informed me that they tried it, but had to switch back to UE 4.23, because they ran into critical issues with the community support for WebGL in newer versions - I don't know any details about those issues, but was told that they were unrelated to Photon).
Also you need to either use version 188.8.131.52 or older (not recommended) or version 184.108.40.206 or newer of the Photon Emscripten Client SDK.
Versions that are newer than 220.127.116.11, but older than 18.104.22.168 do not provide binaries that are compatible to the Emscripten version that UE 4.23 uses, so they won't work correctly with UE in webbrowsers.0