How to reach the true final ending in Sonic Frontiers

Interestingly, Sonic Frontiers contains a true, secret ending that players can access through a rather simple method.

Sonic Frontiers' has its weird, bad hooks in me

How to get the True Ending in Sonic Frontiers - Gamepur

Sonic Frontier's Ending Makes a 'Sonic Boom' Character Canon

Update 3 Final Boss In Base Game [Sonic Frontiers] [Mods]

Sonic Frontiers: How to defeat Giganto, the First Titan

PSA: Don't Miss the TRUE Final Boss in Sonic Frontiers!

Sonic Frontiers True Final Boss Appears In Hard Mode

Sonic Frontiers Secret Ending [Explained]

Did I miss the true final boss? : r/SonicFrontiers

Sonic Frontiers: How to Get the True Ending

Sonic Frontiers: How to unlock the true final boss & ending

Looks like the Final Horizon content is an option you're presented