What should I do if my parents' Thailand Pass registration was rejected due to document issues?

The Thailand Pass registration for your parents was rejected, likely due to unclear document uploads. To resolve this, ensure all documents are clear and re-upload them, preferably in JPEG format. Users suggest that taking clear photos with a phone can help with approval. Once you successfully re-upload, it's important to also verify the PCR test timing, which must be done within 72 hours before departing from their home country.