/admin/v1/Groups works in postman, but not via apex_web_service.make_rest_request

Content

I have the following PL/SQL block:

set serverout on

DECLARE
 p_status_code_o NUMBER;
 p_response_o CLOB;
 l_response_clob CLOB;
  l_parm_names  apex_application_global.vc_arr2;
  l_parm_values apex_application_global.vc_arr2;
BEGIN

  l_parm_names(1) := 'filter';
  l_parm_values(1) := 'members[type eq "User" and value eq "de71071385f941ffbea831164cc76d64"]';
  
        apex_web_service.g_request_headers.delete;
    
        apex_web_service.oauth_authenticate( p_token_url     => 'ATP_SERVER/oauth2/v1/token'