Thank you again for diving in to this. It looks like speechify don't support Danish.
On Resemble AI, they have something like Elevenlabs:
For professional voice cloning through data upload, we require explicit, verifiable consent from the voice talent. This involves providing a clear audio consent statement along with the training data, so that we can confirm the identity. By uploading voice data, you're confirming that you have such consent, which should align with our guidelines. The consent recording must follow our template, e.g., "I acknowledge my recordings will be used by [Your Company] to create a synthetic voice by Resemble AI." For any questions regarding consent, please reach out to us.
I will try to contact them regarding my use, which is neither commercial, nor using "voice talent" exactly.
The Hamburdler for McPresident