DiceBot does not have an external API, only the internal API for the programmer mode.
I do not have the API documents for primedice, you will need to contact PD support/developers for it.

If you strategy has been set up in the advanced mode (if it wasn't, try it. It's probably possible), you can use the auto login and auto start features the bot already has.

Go to View (Top of the screen)-> settings. Enter your username and password, check the auto login check box, check the auto start check box and click on save (bottom right). Every time you open the bot, it will load the most recent settings (As it always does), attempt to log in using the details provided and start betting once logged in. (it will always default to BTC)