Telegram will automatically play GIFs and videos.
This guide will help you to Disable Autoplay in Telegram. I have an Android phone, iPhone and a Windows 11 PC.
Easy Ways to Disable Autoplay in Telegram

Open Telegram and click on the three horizontal lines in the top right.
Choose “Settings” from the menu, which is located between Invite Friends and Saved Messages.
Tap Data and Storage Between Privacy and Security, Chat Settings.
You can find GIFs, Videos and a toggle switch in the Autoplay media section.
The first is for GIF autoplay, while the second is for video autoplay.
You can turn off the toggle switches by turning them.
Turn on the switches above to enable autoplay.
Telegram (iPhone), Stop Autoplay
Launch Telegram, and then tap the Settings button at the bottom.
Choose Data and Storage Between Privacy, Security and Appearance.
You can find GIFs, Videos and a toggle switch in the Autoplay Media section.
Now, turn off both toggle switches.
Turn on the switches above to enable autoplay.
How to Disable Autoplay on Telegram Web

Click on the three horizontal lines in the left sidebar to open Telegram Web.
Select Settings > Data and storage
You will find the Autoplay media section at the bottom.
You can turn off GIFs or Videos.
That’s all.
Turn on the options above to enable autoplay.
That’s it.
Thank you for reading.