Constraining sketches relative to other sketches

I’m new to Shapr3D on iPad. I have a hexagon sketch and want to place a circle constrained to a construction line between the midpoints of the top and bottom hex. Is there a way to constrain geometry in a new sketch to an existing sketch? I’m very familiar with Creo and Onshape, and those programs it seems you can constrain a second sketch relative to construction lines or other features in a first sketch or features of an existing extrusion, for example. Is it possible or am I just missing some simple functionality?

Basically what I’m trying to do here is extrude the hexagonal surface, and then have a circle extrusion on top of that, dimensioned from the center of the hexagon

https://support.shapr3d.com/hc/en-us/requests/new

Not sure why you want to use different sketches for that but you can constraint your circle to the line using midpoint constraint.