How to share a macro with another PC
Use File > Export in Macro by Zaweba to save the .zmacro file, copy it across, then File > Import on the other PC. Check for typed passwords first.

Every macro in Macro by Zaweba lives in its own .zmacro file, so sharing one means exporting that file and importing it on the other PC. Choose File > Export, copy the file across by USB stick, network share or email, then open Macro on the other PC and choose File > Import. The macro joins that PC's library.
The file is plain JSON kept in your Macro folder. That makes it easy to move and back up, and it's also why you should look at what's inside before it leaves your hands.
Before you export
Recorded keystrokes, including passwords, are stored as plain text. Macro warns you about this before your first recording, keeps the warning visible in the editor and repeats it when you export. The warning is also written into the exported file itself, so whoever receives it sees it too.
Open the macro in the editor and read down the steps. Look at every Type step. If one contains a password or anything else private, delete it or replace it with a harmless placeholder. Where a password belongs, you can leave a note step saying so, so the person on the other PC knows to type it themselves.
If you are recording a macro you already plan to share, use the pause hotkey (Ctrl+Alt+P by default) while typing anything sensitive. The macro gets a note where keys were not recorded, and mouse clicks carry on being recorded.
Moving the file
Export puts the macro in a place you choose. Any way of moving a file works. On the other PC, File > Import brings it into the library alongside the macros already there.
If you want to share several macros, export them one at a time. The library also lets you duplicate, rename and delete macros, which helps if you want to keep your own copy and send a tidied version.
Making it work on someone else's screen
A macro repeats clicks at positions. On another PC the screen size, the window layout or the place a program opens can all be different, and a click recorded at one spot might land on something else.
Positions relative to the active window help a great deal. With that turned on, clicks are stored from the corner of the window you were working in, so the macro still finds the right place when that window sits somewhere else. Each step can be switched separately in the editor, so clicks on something fixed, such as the taskbar, can stay as screen positions while the rest follow the window.
Waits matter too. A slower PC might take longer to open a dialog, and a click arriving too early misses. Adding a Wait step before a click that follows a slow action is often the only change needed. Playing the macro at a slower speed, such as 0.5x, is a quick way to check whether timing is the problem.
Hotkeys on the new PC
A macro can have its own trigger hotkey, such as Ctrl+Alt+1. The other PC may already use that combination for another macro or another program. Macro refuses hotkeys that clash, along with plain letter hotkeys, and gives a reason, so you'll know straight away if you need to pick a different one.
Testing after the move
Play the imported macro once at 1x and watch it. A countdown of 3 seconds by default gives time to click into the right window first. If anything goes wrong, hold Esc for one second and the replay stops, releasing any key or mouse button it was holding.
If a click misses, open the step and point at the right place. The editor reads the cursor position after three seconds, which is quicker than working out coordinates. Then play it again.
Other ways to share
Because each macro is a file in your Macro folder, a shared folder or your normal backup will carry macros too. Import and Export are still the clearest route, since they put the warning in front of you and keep each PC's library tidy.