GPS Tracker for bikes/scooters

Hi everyone. Recently I had my e-bike stolen from my work place's parking lot and it was recently bought for 2 months. 3 years ago it happened the same and I had a small gps tracker installed on it, but the thieves noticed it, so it was useless.
Can anyone recommend my a good device that can not be noticed, please?

I spend a lot of time on a bike and use it to run errands frequently.  It would be almost impossible to hide a GPS on a bike.  Inside of tubing doesn't work as it needs an external antenna not inhibited by metal or even heavy tree coverage.  If I must leave it unattended, I use a loop lock and cable to secure the wheels and frame to any railing or permanent mounted structure.  I have seen large cables sliced cleanly so the metal loop type lets you secure it to the external object.  Extraction would be serious and damage the bike, making it useless to ride off.  Good luck and good lock.

I spend a lot of time on a bike and use it to run errands frequently.  It would be almost impossible to hide a GPS on a bike.  Inside of tubing doesn't work as it needs an external antenna not inhibited by metal or even heavy tree coverage.  If I must leave it unattended, I use a loop lock and cable to secure the wheels and frame to any railing or permanent mounted structure.  I have seen large cables sliced cleanly so the metal loop type lets you secure it to the external object.  Extraction would be serious and damage the bike, making it useless to ride off.  Good luck and good lock.

Thank you very much for your response! I visited a bike shop in my country today to buy a new one and the owner told me that he uses a gps tracker which is hidden under his seat and the signal was ok. Do you think that this can be a better alternative? I mean I could use it with a chain attached to a big tree or a very hard structure as a backup but I think that maybe the thieves wouldn't think that there is a device under the seat. this is the tracker: https://www.gps-tracker.info/produkt/gps-tracker-bicycle/

There is another possible solution.

Don't buy a shiny new "High Value" bike - purchase a Second-hand one and treat it to a makeover.

Just a thought: Once:- while in London, many years ago, I watched a thief use an Angle Grinder to cut through the Railings that a particularly desirable Mountain Bike was padlocked to.

The loop I use is a MasterLock, shaped like a slide trombone and can't be cut.  The cable loops between the two loop halves and can be cut but it takes a wire shear, not a bolt cutter.