Does the first generation of airpods supports Dolby atmos?

list of supported devices from Article linked above:

Supported songs automatically play in Dolby Atmos when you're listening with:

• AirPods, AirPods Pro, AirPods Max, or AirPods (3rd generation)
• Beats Fit Pro, BeatsX, Beats Solo3 Wireless, Beats Studio3, Powerbeats3 Wireless, Beats Flex, Powerbeats Pro, Beats Solo Pro, or Beats Studio Buds

Well, let's go over that article a bit to see if we can sort this out for you.

• If you subscribe to Apple Music, you can listen to select songs in spatial audio with Dolby Atmos. That is, as a minimum, your audio source would need to be from Apple Music ... and not all sources meet this criteria.
• You need to make sure that your iPhone is updated/upgraded to the latest version of iOS. Is it? You list iOS 15 in your tagline, but currently 15.3.1 is the latest. Is this what you have?
• The Music app, on your iPhone, needs to be configured for Dolby Atmos. Is it?
• It would have to be configured for either the "Automatic" or "Always On" setting. Which one are you using? Have you tried both?
• In theory, supported (Dolby Atmos) songs will play automatically on your AirPods on the "Automatic" setting. So should they on your iPhone 13. Is this not what is happening for you?
• Do note that Spatial Audio is not available with your AirPods.

Why what exactly? The support article you came here from states what's required for Dolby Atmos on a number of Apple devices, including the 1st gen AirPods.

Because that’s what God wants.