How to use IOL and QEMU device images at the same time in EVE-NG?

Question

QEMU

Hello, I decided to install EVE-NG on my computer, but a problem arose - IOLs of Cisco firmware are normally used, but I cannot use firmware from other manufacturers from QEMU images. At the same time, I do everything according to the official instructions:
1. I create a folder (for example, fortinet-FMG-v6-build1183) along the path /opt/unetlab/addons/qemu/ and unpack the image into this folder
2. I go to the fortinet-FMG-v6 folder -build1183 and use the command: /opt/qemu/bin/qemu-img create -f qcow2 virtiob.qcow2 100G
3. Use the command: /opt/unetlab/wrappers/unl_wrapper -a fixpermissions Everything

seems fine, or am I missing something ? After the procedure, I create a Fortinet node, launch it, it starts and shuts down. What do you advise?