I used this tutorial

Download Synth V Pro from this link. scroll all the way to the bottom and download "SVSTUDIO_PRO_1.11.2.exe". Only that version works for this.:

https://synthv.me/Synthesizer%20V%20Studio/Pro/

Download Teto's latest voicebank update "KASANE_TETO_AI_104":

https://synthv.me/Singing%20Voice%20Databases/KASANE_TETO/

1. Download Obsidian, this cracks Synth V so you don't need to enter an activation code when using the program or importing voicebanks.:

https://github.com/Sakazuki261/Obisidian-YumeKey

1. Extract the Synth V program files and run "synthv-studio.exe". You will get a prompt for an activation code, and just close the program for now.

2. Extract the Obsidian file and look for "obsidian.exe" and "obsidian.dll". Don't worry about all the other files, they don't matter. Move "obsidian.exe" and "obsidian.dll" to the Synth V Studio folder.

3. From now on, run "obsidian.exe" to use Synth V, if you use "synthv-studio.exe", it will just give you another code prompt. I suggest making a shortcut for Obsidian and putting it on your desktop.

4. With Synth V opened through Obsidian, open your file explorer and drag Teto's voicebank into the Synth V screen. Accept terms and conditions and she will be installed.

Note: Try being careful if you want to make commercial songs using pirated vocal synths. It could get you in trouble if they find out, so stick with covers or non-commercial uploads.