Help with watch wallet

I’m using Litecoin Core latest version which would never show any balance although I have records of the transaction when I moved the LTC somewhere. I have figured out and imported my watch only wallet which now shows my balance in a watch only wallet. I have my initial seed phrase from 2017 when I moved my LTC out of Coinbase. I do not remember any of those steps at that time. How do I move watch wallet coins into a Trezor or into LTC Core since the watch wallet is for observation only?

When you mention seed phrase, is it like a set of 12 different words? If so that’s not from Litecoin Core, but a different wallet. Possibly Electrum-LTC or Litewallet (formerly known as LoafWallet). Litecoin uses a wallet.dat file as the method to store your wallet keys.

The seed phrase I initially wrote down in 2017 when I downloaded the LTC desktop app. None of my wallet.dat showed any LTC. Yet I have the transaction info from Coinbase that shows the public address on the block chain. I had no concept of a “wallet” back then. I’m not sure what I did back in 2017. There was no QR code generated at that time.
Using the config box I’ve downloaded a “private key” however, the issue is as far as I can tell, I never put the LTC in any wallet. Although it now exists in the LTC core program as a watch only amount. I’ve backed up the current wallat.dat file with the watch wallet in place. I used the “importaddress” in the config box which is as far as I’ve gotten with it.

Litecoin Core doesn’t have a seed phrase. For reference a seed phrase looks like this:

Where Litecoin Core does have a private key that you can export using the console, which looks like this:

Which one does your look most like, and what’s the first character of the priv key if it’s like the second example?

I’ve used importprivkey for each wallet. They all begin with “T” including the one with the watch-only wallet. I’ve read somewhere using importpubaddress gets the watch only wallet. So this was my mistake in doing that. I’m thinking that what I’ve been calling a “seed phrase” is most likely the encryption key (or a BIP39?). I don’t remember how it was generated since I wrote it down in 2017.
I haven’t tried “exportprivkey” - should that be a next step?
(And a big thank you for responding)