Are you using TurboTax Online? If so, you need to click on Tax Profile on the Tax Home page (2024 tax return on the left), then click on Your Tax Profile. There you need to check off the RL-1. Click Continue to save and then go back to Tax Home > Income >T4. Now you'll see a Box E at the bottom of the T4 page, which is what you need to enter from your RL-1.