If you want to e-sign lease agreements, you don’t need any special software. You can just have the signee type their name in the signature space and email the document back to you. The date of the email will be evidence of the timestamp, and the email records are commonly accepted in court. That’s just as legally binding as Docusign. The reason people use Docusign is to keep track of a large number of legal ageeement…
Although be aware that the specifics of what is acceptable vary from state to state. To say nothing of non-US jurisdictions.
It’s a fundamental principle of common law that agreements are contracts even if you don’t follow some specific procedure (such as pen and paper signatures or Docusign) to agree to them.
In the US, federal law (UCC) deviates from common law jurisprudence by requiring that some contracts be written and signed, but it says that signing is “using any symbol executed or adopted with present intention to adopt or accept a writing” (i.e., anything is a signature if you intend it to be one) and that the symbol may be produced “manually or by means of a device or machine” (e.g. a computer).
In the U.S., Louisiana does not follow common law (they are based on Roman/ pre-Napoleonic French law) but they explicitly recognized electronic signatures in 2006.
So, no, you don’t have to be aware of specifics that vary state to state. You can use email/PDFs/anything else to sign a document anywhere in the English speaking world.