I added custom field to Vehicle doctype and I need to enable (select) Set Only Once for this field, but I can not do this from customization form or from the custom field, I did not find this property. How I can enable it for custom field?
If I add this field in the doctype, then it will be removed when doing upgrade and this will cause to remove the data from the database for this field.
I am also thinking to add it via json file, but again I am afraid it will be removed when doing update.
Any help please?