Hi @noodles w thanks for posting in the community! I'm happy to help answer your questions

To quickly add a line anywhere on your canvas simply press and hold "L" on your keyboard. This will turn your cursor into a + sign and allow you to add a line by clicking and dragging.

This also applies to when you are adding arrows between the lifelines. If you hold "L" and create a line from one lifeline you should be able to easily connect it to another lifeline.

If you are not seeing this it could be because line connections are toggled off in your document. You can check this by navigating to File > Page Settings > Line > Line Connections. 

I hope this helps! Feel free to let me know if you have any additional questions about this. Cheers! :) 

Hi Leianne C Thank you very much for giving me such a details answer and this is only for the first question I mentioned It would help a lot if you give me the second question's answer thanks in advance.

Hi @noodles w sorry for the oversight on the second question! Would you mind sharing some additional details on what you mean by "How did the arrows shift to the lifeline boundary automatically"?

If possible can you please tell me the timestamp where you saw this in the guide video you linked? This will help me take a closer look and share recommendations or features that can help. Thank you!

Hi Leianne C:

the line with the arrows links to the vertical line initially and adding the activation covers the vertical line and then the line with the arrows relates to the activation boundary automatically I was wondering how to do it.

It's about 7:33 ~ 7:40 thanks for your time. 

Hi @noodles w thank you for sharing the timestamp in the video! Upon confirming with our development team it seems like it is expected that lines will not automatically convert the way shown in the video at 7:33 ~ 7.40. Unfortunately it is appearing that way in the video because of video editing and you will need to manually adjust the arrows. 

I'm sorry for any confusion caused! However I can see certainly understand how that option would be helpful when creating sequence diagrams. Would you mind adding your idea to our feature request form? Ideas submitted to this form are passed on to the product development team for their consideration.

Thanks for your request and I apologize for any inconvenience this causes you. Please feel free to let me know if you have any questions about this!

Hi Leianne C thank you very much for the detailed reply it made me less confused thanks again.
I will add the idea to your feature request form in fact I am very much looking forward to this feature lol.

Thank you for adding your request to the form @noodles w! Please feel free to let us know if you have any questions and we'll be happy to help. Cheers! :)