You have to have oral testimony by the plaintiff, in person, and in the courtroom, to obtain a divorce.  Family Law Section 1-203 and Rule 9-209.

That testimony has to be corroborated by someone or something other than the parties to the divorce.  Family Law Section 7-101(b).   A marriage certificate can corroborate the marriage.  A notarized written agreement signed before the complaint was filed can corroborate a mutual and voluntary separation.  Family Law Section 1-104.

But most of your testimony is corroborated by a witness.  That testimony also has to be oral and in court “unless otherwise ordered by the court for good cause”.  Rule 9-209.

What is good cause?  The court has allowed me to use telephone testimony in a handful of cases where the corroborating witness was a geographically distant relative or a busy mental health professional.  In one uncontested divorce, I was permitted to corroborate adultery with the deposition transcript of the paramour, but the judge let me know he would have preferred live testimony.  If you are going to try to corroborate without a witness in the courtroom, call the judge’s clerk or secretary before the trial to make sure it will be permitted.

In an uncontested divorce case in Maryland, the plaintiff needs to appear in court to testify.  The Court of Appeals once issued a rule that allowed for summary judgment in divorce cases so no one would have to appear.  However, the Legislature felt that divorce should be treated as a more serious matter, and so it passed the following law in 1984:

Oral testimony required for final decree.  In an action for alimony, annulment, or divorce, a final decree may not be entered except on oral testimony by the plaintiff in a hearing before an examiner or a master or in open court.  MD Family Law Article, Section 1-203(c).

The defendant need only appear if he or she wants to do so. You will need to bring a witness with you to corroborate the facts of your divorce.