Walky Dog Guard, designed to fit numerous car models. I used this in a Suzuki S-Cross. It expands to fit the space using slide out poles and it clips on to the rear headrests using the adjustable brackets provided.
Sadly, I don't have the box or instructions and I won't be able to confirm if it fits your vehicle. From the invoice from it back in 2017, it is a 'BICE WalkyGuard no. BCA014'. It can't find an exact match on-line, but this looks pretty close https://www.amazon.co.uk/Walky-Adjustable-Barrier-Automotive-Safety/dp/B003...

One of the tightening fittings has a split in it. I think that this causes one of the arms to rattle slightly. I imagine that this could be fixed with a bit of tape or, if like me, you don't need to use the top extension piece, you could take one of the fittings from there to replace the split one.

Generic Dog Guard for your car (Astley Village PR7)