Hi,

Here give the code for requirement ,

Implementation Steps

1. Add Manager Field on Locations

Extend the stock.location model to include a manager_id field:

class StockLocation(models.Model):

    _inherit = 'stock.location'

    manager_id = fields.Many2one('res.users', string="Location Manager")

2. Add Approval Status to Stock Picking

Extend stock.picking to include an approval field and logic:

class StockPicking(models.Model):

    _inherit = 'stock.picking'

    approval_state = fields.Selection([

        ('draft', 'Waiting Approval'),

        ('approved', 'Approved'),

        ('rejected', 'Rejected')

    ], default='draft', string="Approval Status")

    def action_approve_transfer(self):

        self.ensure_one()

        self.approval_state = 'approved'

    def action_reject_transfer(self):

        self.ensure_one()

        self.approval_state = 'rejected'

3. Block Validation Without Approval

Override the button_validate() method:

@api.multi

def button_validate(self):

    for picking in self:

        if picking.picking_type_id.code == 'internal':

            source_mgr = picking.location_id.manager_id

            dest_mgr = picking.location_dest_id.manager_id

            if source_mgr or dest_mgr:

                if picking.approval_state != 'approved':

                    raise UserError("This internal transfer must be approved by the location manager(s) before validation.")

    return super(StockPicking, self).button_validate()

4. Auto-Notify Manager(s)

On internal transfer creation, send activity to manager(s) using mail.activity:

@api.model

create(vals):

    picking = super().create(vals)

    if picking.picking_type_id.code == 'internal':

        users_to_notify = []

        if picking.location_id.manager_id:

            users_to_notify.append(picking.location_id.manager_id)

        if picking.location_dest_id.manager_id:

            users_to_notify.append(picking.location_dest_id.manager_id)

        for user in set(users_to_notify):

            self.env['mail.activity'].create({

                'res_model_id': self.env['ir.model']._get_id('stock.picking'),

                'res_id': picking.id,

                'activity_type_id': self.env.ref('mail.mail_activity_data_todo').id,

                'user_id': user.id,

                'summary': 'Approval Required for Internal Transfer',

                'note': 'Please approve this internal transfer before it can be validated.',

            })

    return picking

5. Add Approve/Reject Buttons (Optional but Recommended)

Add two buttons in the stock.picking form view (inheriting):

<button name="action_approve_transfer" string="Approve" type="object"

        attrs="{'invisible': [('approval_state', '!=', 'draft')]}" class="btn-primary"/>

<button name="action_reject_transfer" string="Reject" type="object"

        attrs="{'invisible': [('approval_state', '!=', 'draft')]}" class="btn-secondary"/>

Hope it helps

Solution:

1. Use Approval Flow with Odoo Studio (Enterprise):
   • Go to Inventory > Settings and ensure Multi-step routes and Warehouse Management are enabled.
   • Create an Internal Transfer (Operation Type: Internal Transfer).
   • Use Odoo Studio to:
     • Add a new field: approval_status (e.g., Pending, Approved, Rejected).
     • Add a button: Send for Approval → Changes approval_status to Pending.
     • Restrict transfer validation (via security rules or domain) unless approval_status == Approved.
2. Assign Inventory Manager Group:
   • Use Access Rights to restrict who can approve (approval_status → Approved).
   • Assign approval responsibility to users in the Inventory Manager group.
3. Automated Email Notification (Optional):
   • Go to Settings > Technical > Automation > Automated Actions.
   • Trigger: On approval_status change to "Pending".
   • Action: Send email notification to Inventory Managers.