What should be included in an employer's letter for a DTV (workcation) application in Thailand?

A user is seeking guidance on applying for a Digital Workcation Visa (DTV) from the UK. They are asking for a template of an employer's letter to confirm their remote working status and inquiring about additional requirements for the letter. They also question the timeline for booking their return flight, specifically if it can be booked for 180 days in advance or within the next 60 days due to entering on a tourist visa. Community comments suggest that a flight booking is not necessary unless requested, emphasize the need for the applicant to remain in the UK during the application process, and advise including permission for remote work in the letter.