Hi Guru,
First, instead of constants, you could consider creating a ‘Settings’ entity in your database where you can store the URL's. The advantage of this is that if the URL ever changes, it's also easy to change it in your database, making your application more maintainable.
Next, like you mention, you could pass an enum per tile, as a parameter to a generic microflow, where you can then use a decision split to decide which URL to use.
Basically you will then have 5 flows all calling the same generic microflow.