The mat and the material you cut on the mat are called "load types" in Design Space (the software for Cricut). Load types include: without a mat, on a mat, multiple ways.
The Cricut help page tells us how to chose the load type:
When you select Make It, a pop-up window prompts you to choose how you will load your materials. Only those options compatible with the size of your design will be available.
It also tells us that:
The maximum cutting area on a 12 in x 12 in (30.5 cm x 30.5 cm) mat is 11.5 in x 11.5 in (29 cm x 29 cm).
A4 is 210mm x 297mm, which is too long for your cutting mat.
There's an important note for Cricut Maker 3 and Explorer 3:
Note: If your design is too large to be cut on a mat but the right size for a Smart Material, the load type will default to Without Mat. If your design has multiple components that are the right size for a mat or a Smart Material, the Multiple Ways option will be available.
That lets me suspect that your .svg file is too big to fit on the mat and the software chooses the "without a mat" setting instead. possible reasons why the design doesn't fit are:
- It's actually supposed to be bigger than you think
- It isn't positioned correctly at the 0 coordinate. The cricit starts cutting in the upper left corner, but if there's a lot of empty space in the .svg file, that tells the cricut to cut more to the right and/or bottom, which can push the design outside the mat.
You should either try cutting a different design just to test whether that works as expected or edit the .svg file to scale it down and make sure there is no empty space around the actual design.