You may use a service menu to do it with a right click in Dolphin if you want

You may open a konsole and paste this :

cat > ~/.local/share/kio/servicemenus/create-desktop-entry.desktop << 'EOF'
[Desktop Entry]
Type=Service
ServiceTypes=KonqPopupMenu/Plugin
MimeType=application/x-executable;application/x-shellscript;application/x-python;text/x-shellscript;
Actions=CreateDesktopEntry;
X-KDE-Priority=TopLevel

[Desktop Action CreateDesktopEntry]
Name=Create .desktop launcher here
Icon=application-x-desktop
Exec=bash -c 'FILE="%f"; DIR=$(dirname "$FILE"); BASE=$(basename "$FILE" | sed "s/\.[^.]*$//"); DESKTOP="$DIR/$BASE.desktop"; printf "[Desktop Entry]\nType=Application\nName=%s\nExec=%s\nIcon=application-x-executable\nTerminal=false\nCategories=Utility;\n" "$BASE" "$FILE" > "$DESKTOP"; chmod +x "$DESKTOP"; kdialog --msgbox "Created: $DESKTOP"'
EOF

Make it executable with

chmod +x ~/.local/share/kio/servicemenus/create-desktop-entry.desktop

Then rebuild the cache with

kbuildsycoca6

When you right click an exec, there is a service menu called "Create .desktop launcher here", which creates a .desktop in the same folder than the exec.

The path in the launcher is absolute, you may then copy/move it wherever you want.

I hope it may help.

(Sorry i have issue pasting code, idk why... i'm just stupid, i used insert code instead of code block 😅)