Migrating from Nginx to envoy

Currently, we're using nginx and planning to migrate to envoy. Unable to get the regex patterns working on envoy.

location ~ /abc/1/[0-9a-f]+/rest/abc {
     proxy_pass $app1;
  }

I've tried with

                  - match:
                      safe_regex:
                        google_re2: {}
                        regex: "/abc/1/[0-9a-f]+/rest/abc"
                    route:
                      cluster: app1

but with no success, so I'd appreciate some help here.

Also how can we enable debug level logs in envoy to troubleshoot?