Well, here’s what I would do if I were in your shoes.

1) in your initial application, did you apply as a freelancer or as a business owner?

I would write an “explanation note” explaining that I work as a freelancer with independent monthly contracts from different clients. Get a letter from a client or multiple clients if you can, stating that you work as an independent freelance contractor with them. Also maybe explain in brief what you do for them. You can use ChatGPT or something similar to help you make this letter, and get them to sign it(on their letterhead preferably). Get one of your clients LLC certification or registration(make sure it’s one of the clients who you are getting the letter from). Merge these together as a pdf.

2) did they ask for confirmed flight tickets or flight details?

If they’ve asked for flight tickets, you need to book your tickets and send those to them. See if you can book a flight that is refundable or one that you can reschedule etc. About the accommodation, you can simply book through the book now pay later option through Agoda as you did before and send it to them.

3) An “employee certificate” can be as simple as you getting a letter on your client’s letterhead stating you work as an independent contractor for them, mentioning what you do for them and the terms etc. Again, use ChatGPT to help you make an employee certificate, it’s easy. Along with this, attach your client contracts. Also, even though they did not ask for this, I would personally attach my most recent tax returns with this because it seems like they aren’t convinced about your regular work/income.