This is an example of how a melodic dictation could be delivered within an online quiz.

Notate the following melody: E major, 3/4 time, starts on b. You will hear two measures of beats on the tonic before the melody starts.
Play melody    You have 3 hearing(s), then the link will be inactive.

The starting note is already entered in the m.1 box. Note names (C, d#, Eb) = quarter notes.
Add tags for other rhythms: F/ = 8th, g// = 16th, Ap = half, B. = dotted-quarter, etc. See tx2Mus Help for assistance.

When you are done with your transcription, click [Copy Answer],  paste (command-V) in answer box below, and save your response.
If you are having difficulty with the tx2Mus interface, you may click the camera icon and upload a photo of your hand-written answer.

Answer:

The tx2Mus interface could be embedded within the quiz question (as above) or provided by a link.
Below is what a finished student answer might look like:

https://www.wmich.edu/mus-theo/tx2mus/
© 2020 - David Loberg Code - code{at}wmich[dot]edu