Trade-in Process for Old Apple Watch After Online Purchase in the Netherlands

I have an Apple Watch that was purchased in Turkey, and I’m planning to buy a new Apple Watch. When I check the trade-in option online, it seems that my current Apple Watch Series 4 is eligible for trade-in when I enter its serial number.

However, it says that I will need to send the old watch via shipping after purchasing the new one online. What I would like to know is this:

If I order the new product online and provide its serial number, can I then go to an Apple Store in the Netherlands with my old Apple Watch Series 4 and complete the trade-in in person? Will they tell me the trade-in value on the spot and issue the refund or store credit there directly?

Or will Apple still require me to send the old watch by mail, even though I’ve already purchased the new one?

I’d really appreciate your help regarding this. Thank you in advance!