Minecraft – Errors while trying to buy Minecraft

I'm able to log into my Minecraft account on my phone, but I can't from my laptop. I'm using this page to log in.
Is that the right one?

I tried to buy the Minecraft Java Edition on my phone, but, after entering all my details and pressing the purchase button, I get a message saying "You need to enter a profile name", even though I have entered a profile name, and it is available.

It feels like someone really doesn't want me to buy this game!

Update

I was able to log into my account with the Minecraft launcher. I clicked the "Buy the full version on the website" button, and was able to log in within Chrome. However, I can't access my profile page.

What the hell is going on?!

Update 2

I tried using Safari instead of Chrome and was able to access my profile. I'm still not able to buy the game though.

This is seriously weird.

Update 3

I tried using Firefox and got a popup when I clicked the purchase button. So far, Chrome, Safari and Firefox have given me different errors. Is the Minecraft website broken or something?

Update 4

I've tested 4 different browsers on 3 different networks and none of them let me buy this game. Maybe someone is trying to tell me that I shouldn't spend $35 on this.