First, Make P6_REGION_ID

that will contain all Region available for your page

use this code as a

select PLUG_NAME, ID from APEX_200200.wwv_flow_page_plugs

where FLOW_ID =:P6_FLOW_ID and PAGE_ID =:P6_STEP_ID

and select list item P6_SECURITY_ID

that will contain all Authorization available for your APP

use this code as a source

select NAME,ID from APEX_200200.wwv_flow_security_schemes where FLOW_ID =:P7_FLOW_ID

and make a process to update Region Authorization

BEGIN UPDATE APEX_200200.wwv_flow_page_plugs

SET PLUG_REQUIRED_ROLE = :P6_SECURITY_ID

WHERE FLOW_ID = :P6_FLOW_ID

and PAGE_ID = :P6_STEP_ID and ID = :P6_REGION_ID end;