Missing cat, what should I do?

Hi,

We’re back from our two days holiday and one of our cats didn’t come back. They both are chipped and I can see from the smart flap cat that she’s not back since two days 🙁

She’s old and not the brightest, so we hope she’ll come back once she find the door open wherever she got trapped.

But, if that is not the case, we’re thinking she might got hit by a car and brought to some vet, how do we know if that is the case? Is there anyone to contact?

The Canton is Zug.

Long Shot but I’ve added a picture.