Using Steam's Proton to run Roblox
Solution 1:
No, there is no way to use Steam's Proton for running Roblox. However, Proton is, I believe, a fork of Wine, which you theoretically can use to run Roblox. From my little experience with Wine, it's quite complicated to use and has some quirks and end up not being a great user experience, but it's basically the only option.
Here is a guide I found on running Roblox on Linux using Wine: Using Roblox on Linux