Work with WooCommerce Bookings plugin?

I have changed using a filter in function.php file

 add_filter( 'woocommerce_booking_single_check_availability_text', 'wooninja_booking_check_availability_text' );

function wooninja_booking_check_availability_text() {
	return "MY CUSTOM TEXT";
} 

Thank you for pointing that you @davinian. The single product pages does indeed need to use it’s own filter for bookings. There’s a couple. I’ll look into adding better support for these in the future.

For anyone else who decided to just use filters.

woocommerce_booking_single_check_availability_text
Default: Check Availability
Just like in @davinian example. This filter will apply on single bookable product pages that require a booking confirmation.

woocommerce_booking_single_add_to_cart_text
Default: Book now
This will change the normal ‘book now’ on single bookable product pages that don’t require booking confirmations.

I hope that helps!