@PhucLe Have a look here for further description of how to organize your mdnotes exports. If you want to prevent mdnotes from overwriting the notes part of your exported file, you have to configure your export behavior with the “split files” option.
Yet, in your case, you actually want your notes/annotations to be overwritten - in a way that they become updated/amended when re-exporting them. I think this is not possible with the mdnotes plugin so far.
I recommend using the prefix/suffix option - that’s at least what I do in order to prevent unwanted overwriting of content: configure mdnotes to name your exported file like, for example, {citekey}-zoteroexport. Once you start working with your note in obsidian, making changes, amendments, adding comments etc., rename it to just {citekey}. Now, whenever you refresh any export from within zotero, nothing will be overwritten - but instead kind of “amended” to your working note.