I had some issues with TLS when trying to get my vpn done …
- you need specify where you have your “ta.key” file resp you have missing “tls_auth” option
- “tls_cipher” better to remove that line (unless you have some other reason to have it)
- you have to specify also “tls_server” (in server config) and “tls_client” (in client config) option and you might want also specify “tls_exit” (in server config).
Here is my setup (it is in CZ, but config files for server,clients are there so you can inspire)
EDIT: as it seems you have some vpn provider, you might want to use this quide (so you use config as is → from your vpn provider) Turris Documentation
the only stuff you usually need to do is copy ca,cert,ta,key files to correct places and reflect such path in your config. I know it is in CZ but code blocks are useful.
EDIT2: there is this quide How to Configure OpenVPN Client on Router - VPN Unlimited (some stuff you can skip for sure, if you have correspond LUCI app for openvpn installed, just jump into the config/setup part) Hope it will help. If you still have some issues, let me know in private message.
Also that provider has some config generators (as app, or as web-app). So you can tailor your config according to their needs (and later you can use it directly or use LUCI to prepare uci/luci syntax like config). And you can also make single ovpn profile having all necessary files (ca,cert,key,ta) inside (which is handy for openVPN 2.4.x based clients (you simply import that file, without any copying another files).Which i believe that vpnunlimetedapp generator can do for you.