@amitkrg
you can't attach a letter if you e-File, and it is not necessary.
Report $31 income on 2021 Form 1040 line 4b and you will be done with this.
That is, you can ignore the 1099-R that comes next year.
you'll have to figure some way to get that amount there because TurboTax does not make it easy.
I've heard TurboTax Online will do it.