Where can I use Amex Gift Card in Canada?

I redeemed my points for a $100 Amex Gift Card (my biggest mistake) because there was a 20% bonus promo. I tried using it on Uber Eats, Amazon and Rogers bill payment, but all transactions were declined. Then, I cannot check the balance online as it kept showing system error.

I called customer service, they confirmed that my card has locked due to fraud prevention. They asked for my name and address to send a replacement card, which will take 3–4 weeks to arrive via Canada Post.

This has been a terrible experience. Has anyone successfully used an Amex Gift Card at any online merchant?