The sha256 checksums for Zorin OS 16.3 are the following:
Zorin OS 16.3 Core 64-bit: 58b99c071958c2039f51ddf2e10e7afb483fed3fcef5d91702bcb5db7b9e2432
Zorin OS 16.3 Lite 64-bit: e01cdba7bb3609f48e7e1b073e46c09cb61b0a964cbd967a537498475937d776
Zorin OS 16.3 Pro 64-bit: f6aa215a802b19f2029e1cc6e15dee35878677e0f27de7c63bf799dc6b2b20b7
Zorin OS 16.3 Pro Lite 64-bit: b82f817495bc9a6e8c045585f473aa6827e7467420d49eb4b36fef24065702cf