We do not support Overleaf for LaTex files at this time due to the Overleaf terms of service. Most of our editors use texworks.
If you have created your LaTex file in Overleaf, you can export your entire project using these directions on the Overleaf help center. Our LaTex team needs to have all the related dependency files along with the LaTex file. You may also include a pdf version of your paper for our reference.