Readonly filed not linking?

HI,in “DocType Naming and Linking” in tutorial 1
the ReadOnly filed that show the first name
its not working for me .
i am worked on the tutorial step by step .
do you have an alternative than the readonly filed ?
thanks

Read Only field should work, check after clearing cache.

Alternative: https://frappe.io/kb/customization/fetch-custom-field-value-from-master-to-all-related-transactions

Inside Child table ,Read only fields do not work neither way
in Child table , how do i link fields ?

here an example
Doc A : Doctype
title:Data

Doc B: child table
doc_a:link to Doc A
title: Readonly ,doc_a.title

Doc C:
doc_b: Table, Doc B

in Doc C title fields does not show , how can i show its info ?

You are right, adding options does not work for child tables.

For child tables, you have to follow 2nd option i.e custom script.