I don’t think there is an NVME to micro SD card adapter that exists at the size needed, but even if you do find one, Unless you already have a very large Micro SD card on hand that you specifically want to use, I would just shoot for a used 256 or 512 SSD on ebay or a local marketplace app.
Now if you want a realllyyyyyy jank solution to use an additional micro sd card on it, you could always get a cheap USB C slim dock with a SD card slot and power delivery and tape it on the back.
I don’t think there is an NVME to micro SD card adapter that exists at the size needed, but even if you do find one, Unless you already have a very large Micro SD card on hand that you specifically want to use, I would just shoot for a used 256 or 512 SSD on ebay or a local marketplace app.
Now if you want a realllyyyyyy jank solution to use an additional micro sd card on it, you could always get a cheap USB C slim dock with a SD card slot and power delivery and tape it on the back.
I would not do that tp my steamdeck in this economy 😂