Ok good. I was not sure, if GitHub wants credit card or is fine with debit card with enabled online payments.
In the linked issue someone tried debit card and it did not work. I have no idea if that was isolated issue or wider problem.
I have lived all my life with only a debit card, the only two instances I experienced of debit card being refused is when booking hotels abroad and renting cars abroad.
So I am pretty sure Github will gladly accept debit cards.
I only had issues with car rental using a debit card in the USA. Debit cards now let merchants "freeze" funds in advance just like a credit card, but that seems to work only in the EU.