Here is my problem,
I have a form view(Parent) in which there is a one2many field, so when I click on the "add line" button, it opens the form view(child) of my linked model (child).
Now the thing I would like to do, is to set the default value for the many2one filed in (child) form view.
How could I achieve such behaviour ?

Here is a minimal reproducible example in pseudo code
Here is a github gist link "gist.github.com/lorenuars19/dd8d7a09f01b414ba2a9fdbdb68cb581"

===> parent.py:

class Parent(models.Model):
	​_name = "test.parent"
	​data = fields.Char("Data")
	​child_ids = fields.One2many("test.child","parent_id")
	​
<===
===> child.py:
class Child(models.Model):
	​_name = "test.child"
	​parent_id = fields.Many2one(comodel="test.parent",string="parent")
<===

next are the xml views

===> views.xml
<odoo>
  <record model="ir.ui.view" id="view_form_test_parent">
    <field name="model">test.parentfield>
    <field name="arch" type="xml">
      <form>
        <field name="data" />
	​   
      form>
    field>
  record>
  
  <record model="ir.ui.view" id="view_form_test_child">
    <field name="model">test.childfield>
    <field name="arch" type="xml">
      <form>
        <field name="parent_id"/>
        <field name="data"/>
      form>
    field>
  record>

<===