Why can’t I text android contacts on my iPad with ios15.1?

An iPad, whether a Cellular model or not, is not capable of directly accessing Cellular Voice or SMS/MMS Messaging features. An iPad with either WiFi or Cellular connectivity alone can only access IP-data services. However, If paired with an iPhone, the capabilities of iPad significantly broaden to include access to Cellular Voice and Messaging services of the associated iPhone - relayed to the iPad over WiFi using Apple’s continuity features.

If you have an iPhone - and both iPad and iPhone are signed-in to iCloud with the same AppleID - to send SMS/MMS messages from your iPad you must explicitly enable Text Message Forwarding for your iPad on your iPhone...

On your iPhone:

Settings > Messages > Text Message Forwarding - set to ON - and explicitly enable your iPad from the list of devices.

Also ensure that Messages in iCloud is enabled on both your iPhone and iPad:

Settings > [Your Name / AppleID] > Messages - set to ON

If you have updated to iPadOS 15.2, you have updated to a beta version. As a beta, you should expect to see bugs and other issues.

With a beta version installed, you are on your own. The Terms of Use that govern participation within these Support Communities disallows any discussion of beta-release software or issues therein.

If you are currently enrolled in a beta programme and wish to return to using the current production version, this support page provides the necessary information to remove the beta from your iPad:

How to uninstall iOS beta software - Apple Support

Be aware that running beta versions, or in restoring production software, data loss may occur.

I did everything indicated above and I am still unable to send a text, why? I just updated to 15.2 earlier today also.