Win 10 to Synology DS via OpenVPN not working

[Aphros]

Hello All,

I'm a first-time user having some difficulty connecting to an OpenVPN server hosted on a Synology DS218+.
I exported the profile and edited the .ovpn file as instructed, but get prompted for a certificate. The cert that is in the exported profile is in .cer format, whereas the client requires a .pk12 format.

How to I resolve this, please?

Regards,
Brendan