Hey! So for me (exact same issue lol) this was solved by connecting my Mojang account (which Minecraft was registered as being owned on) to my Microsoft account, since it had been quite some time since last playing. Hope this helps!
So this turned out to be my Mojang account not being connected to my Microsoft account (or something like that) since it has been a while since I have used either!
JaxonPowell
Hey! So for me (exact same issue lol) this was solved by connecting my Mojang account (which Minecraft was registered as being owned on) to my Microsoft account, since it had been quite some time since last playing. Hope this helps!