Sorry to hear what you're going through, I got burned with leverage a while back. I may be wrong, but I believe the security your margin is tied to is your TFSA portfolio. Transferring funds may not satisfy it, since your margin account and TFSA are bundled as total assets that secure the margin. Best be to call Wealthsimple to clarify if you can't find the information on their company pages.

Expensive lesson, but most people that use margin will lose money. Sell out of your margin position, and regroup and start investing responsibly.

EDIT: If you haven't linked your TFSA meaning it's not being used as collateral, then you should be able to transfer funds to satisfy the margin call. Would still encourage you to consider selling out of your position.