Where is your ADR at Disney Springs and what time? Pre-pandemic, buses would run from the parks to Disney Springs after 4pm, though I'm not sure if that's been suspended in the current environment.
Otherwise, I agree with PP that your best bet is to bus from AK to SSR. You can get off at the Congress Park stop and walk to SSR from there, but the connecting bridge to Disney Springs takes you into the Marketplace side. If your ADR is over on the West Side or Town Center, it can be a long-ish walk. If that concerns you, you can bus to any other resort from AK (AKL would be the closest) and then take the Disney Springs bus from there, which would drop you off at Town Center.
A general rule of thumb I use is to allow 60 minutes to get wherever I need to go on property. In the current environment with limited bus capacity and the fact that Disney Springs buses seem to be few and far between, I might give myself more like 80-90 minutes, especially if you need to transfer to another bus or have to make the long walk from the SSR path.
Lastly, if you have two people over age 18, you could just call two UberX's and split your party up. It would definitely be the fastest - no longer than 30 minutes to arrive there from the time you call it, based on my experience using Uber there back in October.