Regarding the non-immigrant O retirement visa... is it possible to apply while already in Thailand?

If so, would it be possible to do so after entering Thailand with an exemption or tourist visa and possibly after a 30 days extension?

Would the 90-day permit period be added to the initial planned exit date of the tourist visa or its extension?

Thank you for any info!

I am a US passport holder on a tourist visa in Vientiane. I am applying for Thai non-immigrant O (volunteer) VISA. For name/contact of local guarantor in Laos do I just put "self."