Documents required depends on what embassy you go to, so check the website. As to indicating your location, since you actually have to go to that embassy in person that's probably a pretty decent indication of your location.

@Alex ******

it's easy from Canada, you don't need to bank or season funds as affidavits of income are still offered and accepted. Get a Non O online before you leave, that gives you 90 days. The information needed is all shown on the e-visa site and easy to meet. If Manitoba west, use Vancouver consulate, if east the embassy in Ottawa.

Once here, set up an appointment at either the consulate in Chiang Mai or Canadian Embassy in BKK, depending where you live. Get the affidavit of income by providing either pension info, proof of income from CRA or whatever method you have to prove you can support yourself. Take that to the immigration office you would be using along with all the other documents and get the yearly extension. If you are married, get your spouse added as a trailing spouse by getting the fact that you are married an agree to provide for spouse added to the affidavit. Trailing spouse is not extended to same sex marriages, yet, and you may need your original marriage certificate an may need to be translated if not in English. You also both need to have entered on Non O's as it makes it easier so you don't have to leave and get it at a nearby consulate. Easy and no need for an agent.

@Jim *******

that would be the only potential way OP was able to move forward with the application on the e-visa site. It asks what country you are currently in, let's you know if you can proceed, then it ask what embassy/consulate you are using. Just before you submit the application it also gets you to agree that the information you submitted was correct and you have not falsified it. I suppose it depends on how closely they look at the application and if they check IP addresses if they'll approve it. Plus they will have to leave to activate the visa and if the immiigration officer is paying attention to the entry, exits and when the visa was issued... they could be totally hooped. Personally, not something I would do.

@Jim *******

the evisa site asks you for current location. If the location you enter is ineligble it tells you to go to the embassy in the country. If the OP anwered truthfully and entered Thailand as location, he would not have been able to proceed.

@Ivan ***********

yes, correct. My comment regarding applying for the extension is to the person talking about having to leave on the Non O. He has since deleted his comment

@Andy ***********

yes, you are wrong. You don't have to leave, you apply for a new extension.

@Andy ***********

no, you just go through the process for the next extension.

@Lena ******

we switched as well. We actually had approved Non O's but hadn't entered on them yet. When we looked into it, the DTV makes more sense for us. We contacted the Thai Consulate we were dealing with and they said apply, if the DTV is approved they would cancel the Non O's. We lost the Non O fee, but we think it was worth it. My husband was approved in 2 hours, my dependant was just over a day.

Applied through Vancouver consulate and had no issues. Husband was approved in 2 hours, I'm the dependant and it only took 36 hours.

@Bob ********

none of the places mentioned by the OP are using the e-visa system so they must go in person.