'Gen Supoj said the CCSA's operation centre will identify "high-risk" countries before holding a meeting on Friday to decide on the extent to which the "Test & Go" scheme may need to be revised. If the risk of further infections is considered high, the scheme may be suspended completely.'
'Fit to fly' is obsolete. What you need is a negative RT-PCR certificate in English. The result must be issued within 72 hours before your first flight departure.