Single OVPN file from muliple files

I am using the VPN function of my Netgear R8000 Nighthawk X6 AC3200 router and have successfully tested its functionality by downloading the zip fille containing the 4 files (client1.ovpn, ca.crt, client.crt & client.key) for windows and android generated by the router. Using the OpenVPN client on my phone and Win 10 laptop, I can connect to my home LAN. What I wish to do is also connect using the OpenVPN client on my GL-AR150 mini router which I use as my travel router whenever I’m away from home and use my laptop, tablet etc in hotels and restaurants. The problem is this mini router uses a single OVPN file containing the information of the client1.ovpn, ca.crt, client.crt & client.key files. I have tried the obvious which is to cut and paste in the contents into a single client1.ovpn file using relevant tags to no avail. Please could someone advise on how to produce a single OVPN file that would work on my travel router?

Like so:

You can upload the zip archive file from ui directly. It will merge .ca .cert and .key files to .ovpn.