How can I get the block "when web1.GotText" & "call web1.PostText text".

MIT App Inventor Help
1

I'm trying to connect MySql, I saw many user use these blocks to connect db.
Is there any extensions for this, or others solution?

2

These blocks are in the Web component, found in the Connectivity section of the Palette.

3

The tutorial is here

There actually is no need to use an extension for that

To find an extension you can search in the extensions directory here App Inventor Extensions | Pura Vida Apps

Taifun