John Gill Commentary John 20:30

"Many other signs therefore did Jesus in the presence of the disciples, which are not written in this book:" — John 20:30 (ASV)

And many other signs truly did Jesus
Besides these wonderful appearances to his disciples once and again, when the doors were shut about them: and which signs refer not to what was done before, but after his resurrection; and which he did,

in the presence of his disciples ;
for he appeared to, and conversed with no other but them after his resurrection:

which are not written in this book ;
of John's Gospel; though they may be elsewhere; such as his appearing to the two disciples going to Emmaus, and to the eleven on a mountain in Galilee, and to five hundred brethren at once, which other inspired writers speak of.

And many there are which he did; which are not particularly written in this, nor in any other book; for he was seen of his disciples forty days, and showed himself alive, by many infallible proofs; all of which are not recorded.