Try this to start. Put the stats in and see the length of straps you need and angle and height of the part that connects to the trees.

https://theultimatehang.com/hammock-hang-calculator/

Then you can buy webbing that’s 1”+ thick from a number of places. Dutchware Gear has all types. Or you can Amazon some straps that have loops sewn all along so it makes it pretty easy to hang. I like the Bear Butt straps, they are a lot thicker than the cheaper Amazon competitors.

Bear Butt Kodiak Hammock Straps - 40 Combined Loops - 20 Feet Long - Holds 1000 Pounds from Our Extra Reinforced Triple Stitching - Get Our Hammock Tree Straps - Start Up Company https://www.amazon.com/dp/B01D3PSKHI/ref=cm_sw_r_cp_api_glt_fabc_M7529S5RRPF3HKS0QDWV

When you buy straps at a specific length, make sure to take into account the circumference of the trees you are wrapping around and add extra if you decide to get regular webbing straps that require you to tie a removable knot on the end to the hammock sides (like a Becket hitch, which is my favorite).