How to free memory from OpenWrt

I was able to get the bin file from the supplier. Here is the link. https://mega.nz/file/TUF10I4L#c9P_XHETN1R_Wx3MVbFF7WtnKxLvrOC3a3Ohnri0Z5Q

Please I will like to know the openwrt supported device that was targeted or how to remove unnecessary files on it so I can have space to install my software on it.