Custom field in PDF Template

hi everybody, hope you’re fine.
i’m creating a new pdf template for AOS_Quotes module.
a Quote can have a line coming from 3 modules: AOS_Products, Internal Services, External Services.
internal services has 2 field: start_date and end_date. Those 2 fields write the table aos_products_quotes_cstm the column start_date_c and end_date_c.
In the creation of a new pdf template, when i select the Internal Services module, i can not select the 2 fields to put them in the template.
Can you suggest me a tutorial, o can you tell me how to do?

Thank you so mutch! :cheer:


If you have created a relationship between AOS_Products, Internal Services, External Service to AOS_Quotes then only u can add those fields in the pdf.