Can't set Java Profile Name

I have Minecraft Bedrock edition and tried to redeem Java edition on https://www.minecraft.net/en-us/msaprofile/mygames

I was required to set up my profile with Java Profile Name (https://www.minecraft.net/en-us/msaprofile/redeem?setupProfile=true), but nothing happens after submitting username (I entered "adduxa").

It seems that POST request to https://api.minecraftservices.com/minecraft/profile returns 403 Forbidden.

I tried to use different browsers and IP addresses, and to disable adblock - no changes.

Let me know if you need more request headers or other info.