Log into your Sinbad wallet
Ensure you have a USDT balance. To swap your Sinbad balance which is based on USDC to USDT, follow to this guide.
Click on Invest then select USDT.
Click on Send
Enter the amount you want to withdraw then click on continue
Paste the Polygon address you copied in Step 1 above. Acknowledge the disclaimer and Click Send
You’re done! After a few minutes, your receiving wallet balance will show your the transfer.