The Dynex DX-PWLMSE uses a 27 MHz frequency wireless connection between the mouse and a specific USB receiver. For the specifications, see https://www.dynexproducts.com/pdp/DX-PWLMSE/8632063
To use the mouse, you need to press the Eject button behind the scroll wheel. This lets you open the battery/USB storage compartment. Put two AAA batteries into the mouse. Then remove the USB adapter (it's between the two battery slots). Close the storage compartment and put the USB adapter into an available USB 2.0 slot on the computer with a version of the Windows OS above Windows 98. (Note: the specifications I see indicate Dynex wrote drivers for Windows Vista. It may not work with Windows 7, 8 or 10.) Make sure that the computer is on and can get driver updates from on-line sources. Turn on the mouse and it should auto-pair with the receiver. If there is no response, try pressing and holding the connect button on the bottom of the mouse.
I'm not aware of any vendors that sell the USB receiver for this mouse. The manual for the DX-PWLMSE is available from Manuals Lib: https://www.manualslib.com/products/Dynex-Dx-Pwlmse-Wireless-Optical-Usb-Laptop-Mouse-4908.html
I hope this helps.