Any document can be opened by scanning QR code on the mobile device. Transferring the document (signatureRequest) to the mobile device is usually used to disable signing with the mouse. The signer has to use device with touch screen (singing with finger, pen or stylus) for signing. To disable signing with mouse use mouseSignature-false rule.
{
"sendInfoURL": "http://api.okdokument/info",
"rules": {
"mouseSignature": false
},
"filedata": {
"filename":"exampleDocument.pdf",
"content": "xyz_JVBERi0xLjc=="
}
}