ngx.exec is not redirecting in the following condition

Using openresty based nginx.
nginx version: openresty/1.19.9.1
I have a lua file in my project from there I want to call exec method for internal redirection.
My code is something like.. some rest apis call will be there as per result I want to do redirect to some location block

(In lua file)
local redirectToLogFile = function()
local redirecturl = ngx.var.scheme .. '://' .. ngx.var.host .. ":" .. ngx.var.server_port.. "/redirectlog"
return ngx.exec(redirecturl)
end

and correspondingly I have location block in nginx.conf

location ~ /redirectlog {
error_log /usr/local/openresty/nginx/logs/custom.log error;
content_by_lua_block {
ngx.log(ngx.ERR, "calling from the client " .. ngx.var.remote_addr)

}
}
What I observe is some time ngx.exec(redirecturl) is not going to /redirectlog location block when calling the api through browser. same thing is working perfectly when execute via postman.
Is it the correct way. If not how we can achieve this.

Start with the Lua file containing redirectToLogFile and the corresponding location block in nginx.conf; reproduce the behavior through both a browser and Postman while tracing ngx.exec(redirecturl). Confirm whether requests consistently reach /redirectlog and document the conditions that distinguish the two request paths.