request help: how to config browser cache in apisix:2.6

[gewei2000]

Issue description

Environment

Request help without environment information will be ignored or closed.

• apisix version (cmd: apisix version):2.6
• OS (cmd: uname -a):centos 7.5
• OpenResty / Nginx version (cmd: nginx -V or openresty -V):
• etcd version, if have (cmd: run curl http://127.0.0.1:9090/v1/server_info to get the info from server-info API):
• apisix-dashboard version, if have:
• luarocks version, if the issue is about installation (cmd: luarocks --version):

[tokers]

@gewei2000 You may try to add some headers like Cache-Control and Pragma.