If you run with iSmoothRun and a Stryd power meter, then there are various ways to get power data into PowerCenter.
1. You can export the data from iSmoothRun from with the app. You can email yourself the .FIT file of your activity. That file can be imported into PowerCenter.
2. Import your data directly from Stryd with the Stryd app on your phone.
Note that the recording interval in iSmoothRun may not be each second. If the recording interval is not second by second, PowerCenter will show a jagged pace and power profile. This is a limitation of iSmoothRun.