try client setup

compose.yml

@@ -9,6 +9,8 @@ services:
         target: /etc/nginx/conf.d/matrix.conf
       - source: matrix_server
         target: /var/www/.well-known/matrix/server
+      - source: matrix_client
+        target: /var/www/.well-known/matrix/client
     volumes:
       - "public:/var/www/app/public"
     networks:
@@ -28,6 +30,9 @@ configs:
   matrix_server:
     name: well_known_uris_matrix_server_v1
     file: matrix/server
+  matrix_client:
+    name: well_known_uris_matrix_client_v1
+    file: matrix/client
   matrix_conf:
     name: well_known_uris_matrix_conf_v1
     file: matrix/matrix.conf

matrix/client

@@ -0,0 +1 @@
+{"m.homeserver":{"base_url":"https://matrix.lumbung.space/"}}