Barcode Generator - not valid field

[Waldemar]

Trying to set up the barcode generator (Little Appy Co) suggested by airtable - however the content field is not valid. 
I have tried all the suggested field types numbers / auto number / single line text etc but still telling me when I try to generate invalid field. 
Does anyone know what I am doing wrong. 

[TheTimeSavingCo]

Hmm, the screenshot indicates the 'Barcode' field is the problem, and that needs to be an attachment field.  What field type is the 'Create Barcode' field right now?

[Waldemar]

Hi @TheTimeSavingCo : I managed to resolve : I just hadn't set up field correctly - I did just post an Automation issue that I am having real issues with. I'm only just learning but been trying to resolve this for a day and a half. If you have any insight would be great > https://community.airtable.com/t5/automations/automation-add-to-inventory/td-p/193193