apt install tpm2-tools
mkdir usb && mount /dev/sdb1 usb && cd usb
tpm2_createprimary --key-algorithm=rsa2048 --key-context=key.ctx
tpm2_evictcontrol --object-context=key.ctx 0x81000001
tpm2_readpublic --object-context=0x81000001 --format=pem --output=key.pem