Hi Menik thanks for posting in the Lucid community! Yes Lucidchart's UML tool does support autonumbering - simply add "autonumber" to your markup as shown in the example below:

Unfortunately however we're currently experiencing a bug in which this autonumber function adds a duplicate number as you can see here:

Our development team is aware of the issue and I'll be sure to let you know via this thread as soon as I have an update on a resolution. I apologize for any inconvenience this causes; please let me know if you have additional questions or concerns in the meantime!

If anyone else has questions about Lucidchart's UML tool I recommend beginning with our UML Sequence Markup article from the Lucidchart Help Center and posting any additional question in the thread below!

Thank you.

Hi Menik I wanted to follow up on this post to let you know that our development team has resolved the issue with duplicate numbers being added when using "autonumber" in your markup. Thanks for your patience while our team worked on this.  Please give this a try and let us know if you have additional questions!