API / IPN connection between ONTRAPORT (OP) and DIGISTORE24.com (DS)

We need an API / IPN connection between ONTRAPORT (OP) and [login to view URL] (DS) OP is an all-in-one marketing platform and email marketing system (similar systems are Infusionsoft and Active Campaign) DS is a German marketplace and affiliate store and works very similar like [login to view URL] Please find attached a small description what the job is about. Please let us know if you can do the job and which price you will charge for ‘Phase 1’ and send us the offer including one or two sentences if you are experienced with this kind of work and/or if you have experiences with ONTRAPORT or DIGISTORE. Initially ‘Phase 1’ from the description has to be done and offered and we think that within the working process you will get a closer idea how to handle ‘Phase 2’ and how much effort it will take.