403 Forbidden on WooCommerce wc-auth with TMDS plugin callback

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Hello,

I am hosting my WordPress + WooCommerce website on OVH: anderias.be.
I am trying to connect a plugin called TMDS – Dropshipping for TEMU and WooCommerce.

The plugin uses the WooCommerce authorization endpoint:

https://anderias.be/wc-auth/v1/authorize/?app_name=TMDS&user_id=1&scope=read_write&return_url=https://anderias.be/wp-admin/admin.php?page=tmds-auth&callback_url=https://anderias.be/wp-json/tmds/auth

When I open this link, instead of getting the standard WooCommerce “Authorize application” screen, I always receive:

403 Forbidden – You don’t have permission to access this resource.

Important details:

The basic test https://anderias.be/wc-auth/v1/authorize?app_name=test&scope=read&user_id=1&return_url=https://anderias.be&callback_url=https://anderias.be works fine (so wc-auth itself is available).

The REST route /wp-json/tmds/auth is correctly registered by the plugin (it exists, but only accepts POST requests).

I have already tested with Wordfence disabled and with OVH WAF (ModSecurity) disabled → same 403 error.

I also re-saved permalinks, and the problem persists.

It looks like the server configuration (Apache/Nginx or ModSecurity rules) is blocking the POST request to /wp-json/tmds/auth when used as a callback in wc-auth.

Could you please:

Check why this endpoint /wp-json/tmds/auth is being blocked when called through wc-auth?

Whitelist or allow POST requests to /wp-json/tmds/* on my hosting, so the TMDS plugin can complete the WooCommerce authorization process.

Thank you very much for your help.

Best regards,