You did not tell us where you are located, but you may find it is easier/cheaper to buy another functioning trike, than to match & find & replace this one. If the fork is "badly bent" there may be other damage to the frame or other parts, which could be additional hassle/expense.
If you want to replace, you will need to know the wheel size, the steerer tube size (diameter) & length, oh, and rake for good measure. These will determine what replacements might be available. Wheel size should be written on rim and/or tire. I am assuming it is a 1" steerer tube? maybe someone will know for sure? The steerer length you will need to measure, to measure accurately best to have the fork off, which would also give opportunity to measure diameter. With this info in hand, folks here could help you find a replacement.

If you don't have a sentimental attachment to this bike, I would honestly start by looking at your local craigslist/offerup/facebookmarketplace for "Trike" or "Adult Trike" and see what is available. Where I am there are numerous functional trikes available for about the price of a replacement fork.

One more thought, if you have a bike co-op near you they might be able to help with the swap and finding replacement. Good luck

Edit: OP buried the lead, Fork was bent from torque of electric hub motor on front wheel. Wants beefier fork to handle motor.