I was not aware they weren't already available - Thailand ratified the 1968 Vienna treaty in May 2020. - So this is for people with a 5 yr Thai licence who wish to drive whilst abroad.
The OP is referring to IDPs issued under this convention. (Vienna 1968)
They last for 3 years so long as your licence is valid. Anyone from Europe who has an IDP will have this.
To get the Thai one, you will need a full 5 year Thai licence for the category(s) you intend to drive.
There seem to be some "good" fakes about - I saw a tHai IDP in England that was valid for 5 years - this is not possible, but the IDP itself looked 100% genuine.
Some countries, notably the US, haven't signed this treaty - the understanding is that Thailand still recognises IDPs issue under the Geneva treat of 1949 - otherwise some countries will have a problem