Jesus 'signified' & made known by Symbols & Figures the Truths within The revelation of Revelation.

"Amillennialism is one of four views of the end times
regarding the 1,000-year reign of Christ.

"Each of the four views differs in the placement, or the timing,
of the 1,000-year reign mentioned in Revelation 20.

"An amillennialist sees the 1,000 years as spiritual and non-literal,
as opposed to a physical understanding of history.
Although the prefix a- would typically signify a negation of a word,
the amil position sees the millennium as “realized,”
or better explained as “millennium now.”

"To simplify, amillennialism sees the First Coming of Christ
as the Inauguration of the Kingdom,
and His Return as the Consummation of the Kingdom.

"John’s mention of 1,000 years thus points to all things
that would happen in the church age.

"The amil position sees the book of Revelation
as having numerous “camera angle” approaches.

"For instance, chapter 19 ends
with Christ Returning to destroy His enemies,
making chapter 20 difficult to understand
in that enemies arise to attack Him again
(what enemies are these, if they’ve already been destroyed?).

"However, if we see chapter 20
as a different “angle” for the end of the age,
then the 1,000-year reign isn’t necessarily
physical/earthly history, but symbolic.

"It speaks of the spiritual realm. John is giving a “replay” of what he saw.

"Scripture uses the number 1,000 many times
as a generic term to mean
“immensity,” “fullness of quantity,” or “multitude”
(e.g., Psalm 84:10; Job 9:3; 1 Chronicles 16:15).

With the repeated symbolic use of 1,000,
it is difficult to see its use in Revelation as literal,
especially in a book as heavily symbolic as Revelation is."*

And, in which we are INSTRUCTED
to have us KNOW that REVELATION is SYMBOLIC.

We are NOT to:
"take it literally, if you can and if not, then take it Symbolically",

which is = No Hermeneutic Method of Interpretation at all, i.e.,
WHO determines whether each Words are Words of Literal Facts
or Words of Spiritual Truths, ABOVE OUR WORLD of 'FACTS'.

Spiritual Truths, are ABOVE OUR WORLD of 'FACTS'
and are IN THE REALM of The SPIRIT.

There is a Supernatural SPIRIT REALM Higher than 'the facts'.

"That is where ALL of THE MIRACLES TAKE PLACE, Right?

And that is where we find the Revelation of Revelation.

"The Revelation of Jesus Christ, which God gave unto Him,
to shew unto His servants things which must shortly come to pass;
and He sent and signified it by His Angel unto His servant John:"

"Signified. Jesus Christ "signified",
i.e. Jesus made known by symbol and figure,
the things which must come to pass.

"Signify" (σημαίνειν) is characteristic of St. John,
to whom wonders are "signs" (σημεῖα) of Divine truths.

For example; "This He said, signifying [by means of an allegory]
by what manner of death He should die" (John 12:33; comp. 18:32; 21:19).

Pulpit Commentary.

4591. sémainó ►

Strong's Concordance;

sémainó: to give a sign
Original Word: σημαίνω
Part of Speech: Verb
Transliteration: sémainó
Phonetic Spelling: (say-mah'-ee-no)
Definition: to give a sign
Usage: I signify, indicate, give a sign, make known.

NAS Exhaustive Concordance.
Word Origin; from séma (a sign, mark)
Definition; to give a sign
NASB Translation; communicated (1), signifying (2), indicate (3).
...

* from: What is amillennialism? | GotQuestions.org