Watch Strap replacement- TomTom
All units in the Spark/Runner lineup (Spark, Spark 3, Runner2, Runner3 and Adventurer) are identical and all the straps are interchangeable. The only straps that will not fit are the ones for the original Runner1 and MultiSport.
TomTom does not offer a repair service, they will replace the device, for free if it is under warranty (assuming the damage is not broken glass or other user caused damage) or for a fee otherwise. You need to call Support to get the process started and find out what your options are. To get the number for Customer Support, select Contact Us at the bottom of this page, select the service required and the product name and click Contact Customer Care and then Phone Us. It will give you the phone number for the country your account is registered under (this can be changed by clicking the flag icon in the bottom right corner of the screen).