I just updated Thunderbird email client to the latest 102.5.1 version and as a result of the conclusion of the update, I was forwarded to a donation page. I tried to do the suggested 20 GBP donation but then it appeared a web page requesting too many personal details, such as name, address, email, etc.
As in current times it is more frequent to read news about major web sites being hacked and all personal data stolen, I would suggest that you refrain yourself from trying to get personal data, in the end you may collect more donations, as it would be in my case. I am sorry but I did not proceed with the donation.
FWIW, every year I've tried to put in a donation.
This year, I am going to politely decline as the support channels in Thunderbird has been less than impressive. I have questions I have in the support forums that just sits there for months and months without even a view (1 view only) and no response.
Until Mozilla can get its act together to support Thunderbird properly, besides the issue with collection of personal data above from the OP, I am afraid they will see more like me who will eventually drop Thunderbird and move to other (properly) supported email clients.
It's 6 months later and I just had the same experience. I went through the PayPal process, and when it returned to the Thunderbird page it asked me for more information "so we can contact you about your donation".
I don't need you to do that, and I don't want you to either. Since this was not optional - I had to fill in the address to continue, and a "123 NoMailPlease Street" address "could not be verified" I just backed out again.
Mozilla, you'll have my donation if you make it easier.