airport

From my experience, if you travel from Phitsanulok airport to other place like to Bangkok. There are 3 main airlines which provide to you. Firstly, Thai lion air, this airline provides jet bridge for you. Secondly, Air asia, you have to walk and go up to the stairs. Lastly, Nok air, it is same as Air asia which you have to walk and go up to the stairs. However, these are from my experience, so maybe in the future they might have some changing (depend on the airline and airport).