Required documents are given here
Make sure that your passport has validity minimum 90 days after the visa expiring date. Without that, you can’t certainly able to obtain the visa. On the off chance, your passport is not able to match the requirement, you have to renew it.
As your entire application process will be conducted online, you have to submit the digital version of a passport during the process.
There is no physical transaction need while making the payment. Make sure that, you have debit or credit card. If you have a PayPal account, you can easily complete the payment process of Azerbaijan Visa For UK Citizens.
E-mail is the only way by which you’ll get the visa. Make sure that, you have entered correct E-mail address. If there is any wrong, you can’t certainly get the visa.