1. Select Edit → Output Format in the endnote.

2. In the options on the left, find and click the "Number" option.

3. In the right window, find and select the "Add asterisk to project" check box under "Literature citation".

4. Click OK to finish the operation.

After this setting, when you reference a document in the reference list, an asterisk will be automatically added before the referenced document.

If you need to add an asterisk next to the author's name in the reference list, there may be different specifications according to different journals. Generally speaking, asterisks are usually used to mark the order of authors, while communication authors usually put asterisks next to their names. However, please note that different journals may have different labeling methods, so please find out the specific rules about asterisks in the journal guide you submitted.