Yes you can but the textbox will have to be linked to an entity and attribute within your domain model.
Sometimes what people do is to create a non-persistent entity, create a variable and use that variable within your page.
I think, you are expecting the text entered in a textbox needs to be passed to microflow.
Yes you can pass the entity which has the attribute connected to the textbox as a parameter to the microflow.
Following documentation will help you