Create .desktop files on arch linux

If you manually downloaded an application that was not setup by pacman or any other automated setup process, then you will need to create a .desktop file. Else,
ROFI or any other similar software will not be able to find / list your software.

These .desktop files get stored in different locations. Most of them are under:

/usr/share/applications

There you can create a new file for each desktop entry. Example below:

[Desktop Entry]

# The type as listed above
Type=Application

# The version of the desktop entry specification to which this file complies
Version=1.0

# The name of the application
Name=logseq

# A comment which can/will be used as a tooltip
Comment=A privacy-first, open-source knowledge base

# The path to the folder in which the executable is run
Path=/home/user/Software

# The executable of the application, possibly with arguments.
Exec=./logseq.AppImage

# The name of the icon that will be used to display this entry
# Icon=logseq

# Describes whether this application needs to be run in a terminal or not
Terminal=false

# Describes the categories in which this entry should be shown
# Categories=Knowledge base;

More resources regarding this topic:

Desktop entries - ArchWiki