Hii,

please try this 

Activate Developer Mode

create  Automated Actions.

Click “Create” and fill in the following:

• Name: Move to Proposal on Quotation Sent
• Model: Sale Order
• Trigger: On Update
• Apply On: Add a domain to filter only sent quotations:

[('state','=','sent')]

Add Python Code in the Action (Server Action)

Paste this in the Python Code section:

if record.opportunity_id:

    proposal_stage = env['crm.stage'].search([('name', '=', 'Proposal')], limit=1)

    if proposal_stage:

        record.opportunity_id.stage_id = proposal_stage.id

i hope it is use full

Hi,

Please refer to the following links:

1. https://www.youtube.com/watch?v=BBFSTxG9WKI

Hope it helps.