When you first start using Warpcast you've been given an initial allowance that enables you to post a message aka cast. Each user is allocated a limited amount of storage for 5000 casts, 2500 reactions and 2500 follows.
If you want to send more than that number of casts, reactions or follow more users you'll need to purchase additional storage. It's really easy to do directly in the app without having to interact with any frames, which the one's I have seen so far require you to hav ETH on Optimisim...and if you don't bridging to yet another chain would take even longer.
Here is how you can buy more storage directly in the app:
Click on your PFP
Click the settings cog wheel
Click storage
Buy more storage
That it, that's all you need to do to increase your storage on Warpcast!
Mercer AI