Can I use monthly income deposits to apply for a Thai resident visa?

Better off to transfer the money yourself from your UK bank. Keep control. If one monthly payment is late, you have to start the whole process again. Same applies if one payment in 64,900 baht through currency fluctuations. It won't count

baht monthly works from the second year easily,I do not know how it should work for the first year

You're not talking about any "resident visa" you're talking about the visa based on being over 50 (retirement)

While you can get the initial 90 day Non-O visa from the thai consulate in your country by showing funds there in the UK you will not be able to get a year extension on that visa using monthly income by transfer to a thai bank account 🙁 At least not for the first year extension you won't

𝗱𝗼𝗲𝘀 𝗺𝘆 𝗰𝗼𝗺𝗮𝗽𝗻𝘆 𝗶𝘀𝘀𝘂𝗲 𝗺𝗲 𝘄𝗶𝘁𝗵 𝘀𝗼𝗺𝗲 𝗸𝗶𝗻𝗱 𝗼𝗳 𝗰𝗲𝗿𝘁𝗶𝗳𝗶𝗰𝗮𝘁𝗲, 𝗮𝗻𝗱 𝗶𝗳 𝘀𝗼, 𝘄𝗵𝗼 𝗱𝗼 𝗜 𝗰𝗼𝗻𝘁𝗮𝗰𝘁 𝘁𝗼 𝗴𝗲𝘁 𝘁𝗵𝗮𝘁 𝗰𝗲𝗿𝘁𝗶𝗳𝗶𝗲𝗱 𝘁𝗼 𝗽𝗿𝗼𝘃𝗶𝗱𝗲 𝗺𝗲 𝗽𝗿𝗼𝗼𝗳 𝗼𝗳 𝘁𝗵𝗶𝘀 𝗶𝗻𝗰𝗼𝗺𝗲?

The UK embassy here hasn't issued the income affidavit notary letter since end of 2018 <- and that was the ONLY letter you could use to show you get the money from the UK to meet the requirements.

Since that date IF you want to use monthly income you have to transfer in a minimum of 65k baht a month each month every month for the previous 12 months before you apply for a year extension.

As you can see because you need 12 months of incoming international transfers to get the year extension you can't use that method for the first year.

𝗖𝗮𝗻 𝗜 𝗴𝗲𝘁 𝗶𝘁 𝘄𝗶𝘁𝗵𝗶𝗻 𝘁𝗵𝗲 𝗨𝗞 𝘃𝗶𝗮 𝘁𝗵𝗲 𝗧𝗵𝗮𝗶 𝗲𝗺𝗯𝗮𝘀𝘀𝘆 𝘁𝗵𝗲𝗿𝗲, 𝗼𝗿 𝗳𝗿𝗼𝗺 𝘁𝗵𝗲 𝗲𝗺𝗯𝗮𝘀𝘀𝘆 𝗶𝗻 𝗕𝗮𝗻𝗴𝗸𝗼𝗸.

Nope, and no. You cannot

The first year extension you get inside thailand you would need to bank 800K baht in a thai bank account in your name only for 2 months before you could apply for it from a Non-O 90 day visa