Upgrading wkhtmltopdf on Odoo.sh is not directly supported because Odoo.sh environments are managed and maintained by Odoo itself, including the versions of system-level dependencies like wkhtmltopdf.

However, there are some approaches you can consider:

1. Check Compatibility with Odoo

Odoo explicitly supports specific versions of wkhtmltopdf:

• Odoo 14, 15, and 16: Supports wkhtmltopdf 0.12.5 (patched qt).
• Odoo 17 and above: Compatibility may extend to newer versions like 0.12.6, but it’s essential to check official Odoo documentation or confirm with Odoo support before proceeding.

Upgrading wkhtmltopdf beyond the supported version may cause rendering issues for PDF reports.

2. Custom Odoo.sh Deployment (Not Recommended for Regular Users)

While Odoo.sh doesn’t allow custom modifications to system dependencies directly, you could:

• Request Odoo support to upgrade the wkhtmltopdf version on your instance.
  • This is dependent on their policies and whether the version is officially supported.
• Fork the codebase and set up your own Odoo instance on a custom server (not Odoo.sh) where you can control the environment.

3. Alternative Workarounds

If upgrading wkhtmltopdf is necessary and you cannot use a custom server:

1. Request Feature Upgrade:
   • Open a support ticket with Odoo asking them to add support for wkhtmltopdf 0.12.6. If this aligns with their roadmap, they may update Odoo.sh environments.
2. Use a Pre-Rendered PDF:
   • For specific templates, use external tools to generate PDFs and upload them to Odoo instead of relying on wkhtmltopdf.
3. Custom Docker Containers (Applicable for Non-Odoo.sh Deployments):
   • If you manage Odoo on a self-hosted platform, you can modify the Docker container to include wkhtmltopdf 0.12.6.

4. Validate the Need for the Upgrade

Before insisting on upgrading to wkhtmltopdf 0.12.6:

• Check if the features or fixes in the new version are critical for your requirements.
• Validate that Odoo’s QWeb templates and rendering mechanisms are compatible with the newer version.

Conclusion

For Odoo.sh environments, direct control over wkhtmltopdf versions isn’t available. It’s best to reach out to Odoo support for clarity or migrate to a self-managed deployment if you require control over system-level dependencies. If you need further assistance, let me know!