I actually just had my 8′ ISLE Inflatable SUP bust on me a month ago in Hawaii. After flying back to California I was told by the manufacture that it is out of warranty and that they cannot fix it for me. So after doing my research I got a hold of ULI Boards in Sand Diego and they were able to fix the 9 inch seam blow out for only $125, plus they shipped it back to me for free. If you cannot make the repair yourself (which in my opinion can be a lot more complicated then just applying a patch) ULI Boards repair service is the way to go. They have been making and repairing inflatable boards since 2001.
Here is a link to their page https://uliboards.com/product/repairs/
I highly recommend having your board professionally repaired to avoid potential issues in the future.