With regard to oval locks, the Danalock 3 which is on the official list that @sidjohn1 Already linked to will fit many oval locks. This is a Danish company and makes products for both UK ovals and euro ovals. It fits over the inside thumbturn handle. You can email them a picture of your lock and they will tell you if it will fit.
Recently, though, the Nuki has become more popular for this.
Tagging @RBoy
It doesn’t have an official integration, but if you subscribe to Rboyapps ( there is a one time lifetime subscription fee of around £40 which gives you access to their full library of code), they have a very good custom integration for the Nuki.
See the following discussion thread (the topic title is a clickable link)