Better you get the Visa from here. It will save you from long queue and hurdle. I believe free visa offer is there till 31 March 2019. Please check with a travel agent.
Passport or travel document with a validity not less than 6 months Visa application form (filled out) One(1) recent 4x6cm. photograph of the applicant Round-trip air ticket or e-ticket (paid in full) Proof of financial means (20,000 baht per person/40,000 baht per family)