How to use `@ts-ignore` for a block

You can't.

As a workaround you can use a // @ts-nocheck comment at the top of a file to disable type-checking for that file: https://devblogs.microsoft.com/typescript/announcing-typescript-3-7-beta/

So to disable checking for a block (function, class, etc.), you can move it into its own file, then use the comment/flag above. (This isn't as flexible as block-based disabling of course, but it's the best option available at the moment.)

You can use //@ts-nocheck at the top of the file Files

reference: Ignore all errors in a typescript file

You can't. This is an open issue in TypeScript.

There is

// @ts-nocheck

It can be added at the beginning of the file and all errors in it will be ignored, isn't the block specific answer you are looking for but in some scenarios it is equivalent.

https://devblogs.microsoft.com/typescript/announcing-typescript-3-7/#ts-nocheck-in-typescript-files