Hii,
Make sure CRM is installed
Go to Apps > CRM → ensure it's installed.
Set the form model to crm.lead
Edit your website form (Website → Forms), and under “Model”, select:
crm.lead (Lead / Opportunity)
Add required fields
Add at least:
- 
name (Lead title)
- 
contact_name
- 
email_from or phone
Odoo hides the opportunity option if essential CRM fields are missing.
Set the action to “Create an Opportunity”
If still missing:
- 
Go to Website > Forms > Your Form
- 
Under the “Action” section:
- 
Choose “Create an opportunity”
 
If the option is still not there, check that the form's model_id is crm.lead.