my device model is TP-Link TL-WR941N/ND v4, Architecture is Atheros AR7240 rev 2.
The current firmware installed is OpenWRT 18.06.5 r7897-9d401013fc / LuCI openwrt-18.06 branch (git-19.309.48729-bc17ef6)
I do not know how to find the compatible package from the following 19.07 link;
appreciate your support
That model really doesn't have enough memory to run 19.07. The release build exists only as an initramfs because of the small flash. initramfs builds run entirely from RAM, which is not suitable for user deployment because settings cannot be saved.
If you want to try, it has been ported to ath79 (http://downloads.openwrt.org/releases/19.07.0/targets/ath79/tiny/) but you will need to either use Image Builder or a complete custom build to make a sysupgrade image that is small enough to fit in the flash.