[byuu]

You can't be the first to register on every platform out there. If you ever become successful enough, people are going to impersonate and false flag you anyway. You have to balance putting your beliefs out there, so people know an obvious fake; with not over sharing to the point you annoy people with differences from you, which I can tell you first-hand is hard to recover from.

After that, make a links/contact section on your website to list all your accounts. Post a note that anything not on the list is an imposter or someone coincidentally using the same name as you (which does happen, especially when you naively pick a four-letter name.)

Anyone still conflating a false account with you with one step to verify it as a fake will be acting in bad faith regardless.