

Please give me some advice and instructions on how to do it. like how we draw when we have several actors.

I need just a guide on how to draw a complete checkout and make a purchase sequence diagram separately. I created a sequence diagram for login, but I don't know if I have to take authentication as an actor or not. I'm trying to sketch some use cases, but for example, when it comes to completing checkout, there are many actors, and I'm not sure how to do it when there are more actors. This website UML sequence diagram is created using pre-made symbols and. I googled and learned about sequencial diagrams, but I didn't find anything like this. UML sequence diagram is used to document the dynamics in an object-oriented system. For example, when I come to the checkout sequence diagram, I can assume that the procedure is done through view items, but in the view items sequence diagram, I must clearly draw the procedure sequence.

According to this use case diagram, I have to draw a sequence diagram for each use case except login by making an assumption.
