I've been using Perplexity for my AI needs and just seen they have an offer of 12 months free for Pro. However, you do have to add your Paypal account
There are other offers if you are a Virgin Media Media or O2 customer, but most of us have Paypal 
Steps:
1. Access the promo link : perplexity.ai/joi…ion
2. Click on the button "Request 12 months of Perplexity Pro"
3. Create a new account with an e-mail address that is not yet registered
4. Enter the confirmation code that you will receive by e-mail
5. Connect your PayPal account
6. Accept the 12 months offer
7. Log-in to confirm Pro Subscription.
To avoid auto renewal, go to Paypal > Settings > Payments > Cancel Automatic Payments and look for Perplexity and cancel.


Steps:
1. Access the promo link : perplexity.ai/joi…ion
2. Click on the button "Request 12 months of Perplexity Pro"
3. Create a new account with an e-mail address that is not yet registered
4. Enter the confirmation code that you will receive by e-mail
5. Connect your PayPal account
6. Accept the 12 months offer
7. Log-in to confirm Pro Subscription.
To avoid auto renewal, go to Paypal > Settings > Payments > Cancel Automatic Payments and look for Perplexity and cancel.