I bought a few of these with the intention of making a few Bluetooth mouse projects, since it's stated that it has HID functionality: "Bluetooth Profile HID v1.1 SPP v1.2." Serial mode works. So that part is great, but not the part I needed. Seller quickly responded and sent another model that did what I needed.
Response from BurgessWorld Custom Electronics | Oct. 28, 2019
Hi, I am following up on the issues you had with this item. It turns out that this module does not support HID mode, even though all of the suppliers I have contacted say it does - the functions are simply not in the firmware. I have noted this on the product page and will stop selling them when the current stock is exhausted.
However, I have found another bluetooth module to source that actually does HID mode and is configurable with a lot of information online explaining how to set it up and use it in both modes. It is the HM-10, which was a previous iteration of this module that has better firmware and community support. I have a few on order and would be happy to send you one free-of-charge if you would like.