At this time, Stryd does not take the stroller into account. It is not easy to determine the extra effort required as there are many things to consider such as mechanical resistance and weight. Inside Science published this article that suggests pushing a stroller ads 5% of effort. Until Stryd develops technology to automatically adjust for pushing a stroller, you can increase the weight set on your Stryd with 5% to get a better power number on the watch.
When the weight is adjusted, power will be higher. This will also reflect in a higher Run Stress Score so that the metrics and trends are updated correctly.