S&s isa cash pie

Is there anyway to create a pie just for cash within the stocks and shares isa. As interest rates are higher with in the S&s isa, I’d like to keep some cash specificity within the isa that cannot be invested.

If you deposit money into your s&s isa that money will earn daily interest of 4.6% until you decide to invest. This paragraph is from the trading212 app,

Earn daily interest on your cash

How it works

  • We pay you daily interest on your cash
  • Your cash remains instantly available for withdrawal or investing
  • No commitments, disable at any time

Current rates

GBP 4.60%

Yes, I’m aware of this, however, rates in the casinos are 4.35, I’d like to keep the extra cash within the S&s isa, in its own pie, to avoid investing surplus cash