Yeah, actually they had to be ten labours, yet Eurystheus invalidated two of them and added two more (see Pseudo-Apollodorus).
With reference to the OST, all tracks come under the Pixabay licence (https://pixabay.com/service/license-summary/). Here they are:
Cover: https://pixabay.com/music/mystery-ancient-181070/
Intro: https://pixabay.com/music/ambient-ancient-ambient-144655/
Eurystheus: https://pixabay.com/music/main-title-ancient-rhythm-119039/
The Nemean Lion: https://pixabay.com/music/beats-cinematic-soundtrack-ancient-egypt-869/
The Lernaean Hydra: https://pixabay.com/music/ambient-dark-ambient-liminal-background-music-lost-in-...
The Ceryneian Hind: https://pixabay.com/music/solo-classical-instruments-medieval-music-castle-of-dr...
The Erymanthian Boar: https://pixabay.com/music/folk-floralia-194076/
The Augean Stables: https://pixabay.com/music/vintage-anonymous-composers-caccia-medieval-music-1152...
The Stymphalian Birds: https://pixabay.com/music/pulses-medieval-sands-158704/
The Cretan Bull: https://pixabay.com/music/folk-pilgrimage-ancient-mediaeval-harp-174049/
The Mares of Diomedes: https://pixabay.com/music/modern-classical-thesatyrsdance-167125/
The Belt of Hippolyta: https://pixabay.com/music/main-title-ancient-wind-112528/
The Cattle of Geryon: https://pixabay.com/music/meditationspiritual-peaceful-ambient-background-music-...
The Apples of the Hesperides: https://pixabay.com/music/pulses-piano-ambient-background-music-an-unknown-journ...
Cerberus: https://pixabay.com/music/ambient-dead-space-style-ambient-music-184793/
End: https://pixabay.com/music/modern-classical-in-horto-207605/