Hi IOG
MYOB have repeatedly advised they will not be updating any v19 product to STP, so the answer is no 'your software provider has not implemented the Single Touch API into their software'.
MYOB is instead forcing all users to upgrade to AR2019 and pay an annual subscription for each and every file you use for STP. If considering this (AR2019), please do your research and spend some time on the forum to get a good understanding of some of the issues faced by v19 users who upgrade.
FYI there is a software developer who has implemented the Single Touch API for MYOB v19 users. At this stage this is the best alternative as many CSV upload options expire 30 June 2018. If you would like details about the Single Touch solution for v19 users, send me a private message. MYOB don't like this sort of information posted on their forums, as they prefer you upgraded.
To send a private message hover your mouse on my name above and click Send Message.
Regards
Gavin