Hi, there,

The above answer is available and there is another solution, which allows you to upload more than one file one time.

Try this(for example):

Step1( add in the py file):

field_name = fields.Many2many(comodel_name = "ir.attachment", relation = "m2m_ir_attachment_relation", column1 = "m2m_id", column2 = "attachment_id", string = "Attachments", )

Step2(add in the XML file):

Hope it is useful.