Your trailer has an Alpha Systems TPO roof membrane. You can download the entire "care, inspection, maintenance and protection series" here:
https://www.alphallc.us/product-care/
Note the comment in the first section, Roof Cleaning and Care:
"The Alpha roof membrane is quite inert and will resist weathering well; nor does it require the periodic application of products to protect it from ultra-violet light or ozone. In fact, these products can often cause damage to the roof membrane."
This is one of those situations where "if it ain't broke, don't fix it"....
That does not mean "NO INSPECTION"... you need to be on your roof 3 or 4 times a year, carefully inspecting the sealant, the membrane, the aluminum molding (especially the screws) for any signs of leaking or potential leaks.
Take a look at the entire Alpha Systems use/care series, lots of great information available to ease your mind about your roof.