• From issue here

Your problem is that you've got KONG_ADMIN_GUI_URL incorrectly set, causing Kong Manager's Admin API requests to be rejected due to CORS protection.

• You need to set KONG_ADMIN_GUI_URL correctly.

  KONG_ADMIN_GUI_URL=http://YourServerURL:Port

  such as:- KONG_ADMIN_GUI_URL=http://66.107.66.145:8002

OR

• As this answer here allow called from any domain by set

  KONG_ADMIN_GUI_URL=*

Note: Be sure to put the asterisk in double-quotes when defining it with a yaml file, or with a docker compose file.

KONG_ADMIN_GUI_URL: "*"