Unable to complete payment: Payment page shows Forbidden.

[kiddyyang]

Once I click the 'Proceed' button, it will redirect to 'domain.com/payment/gateway/bkash/' page with 'Forbidden - You don't have permission to access this resource.'

I also checked the permissions of the file, and it seems to be fine.
root@4979563b217d:/bitnami/moodle/payment/gateway/bkash# ls -l
total 64
drwxrwxr-x 4 daemon daemon 30 May 26 22:25 amd
drwxrwxr-x 3 daemon daemon 64 May 26 22:25 classes
drwxrwxr-x 2 daemon daemon 25 May 26 22:25 db
drwxrwxr-x 3 daemon daemon 16 May 26 22:25 lang
-rw-rw-r-- 1 daemon daemon 35178 May 26 22:25 LICENSE.md
-rw-rw-r-- 1 daemon daemon 2076 May 26 22:25 pay.php
drwxrwxr-x 2 daemon daemon 21 May 26 22:25 pix
-rw-rw-r-- 1 daemon daemon 5056 May 26 22:25 process.php
-rw-rw-r-- 1 daemon daemon 4426 May 26 22:25 README.md
-rw-rw-r-- 1 daemon daemon 1154 May 26 22:25 settings.php
drwxrwxr-x 2 daemon daemon 47 May 26 22:25 templates
-rw-rw-r-- 1 daemon daemon 1252 May 26 22:25 version.php