“S’il vous plaît que …” : “If you like that …”

It is used alone for “please” but it doesn’t have any other meanig without a subordonate.

S’il vous plaît means: if it [what is going to be said by the speaker] pleases you, literally. On its own, it means /please/ in English. As in please and thank you.

Beyond that, there are two impersonal situations:
S’il vous plaît de dire: If you like saying that etc.

S’il leur plaît de nager les dimananche, etc. If they like swimming on Sundays

or less frequent: S’il vous plaît qu’elle aille de bonne heure. Usually expressed as: Si cela vous plaît qu’elle aille de bonne heure. If you would like her to go earlier.

In English, the S’il vous plaît QUE would be translated with a would.
Rule: S’il + indirect object pronoun + plaire (plait ou plaisait etc.)

The non-impersonal situation is the straight reflexive form of the verb:

Examples: Cela me plaît

La neige ne leur plaît pas

Le filme ne leur a pas plu

Les comédies leur plaisaient bien à l’époque

All those are literally passive constructions. The snow was not pleasing to them. Idiomatically: They don’t like the snow.

The rule here to say that you don’t like something with the reflexive is form: Noun + indirect object pronoun + the verb plaire.

Plaire = to please

Vous plaire = to please you

Il vous plaît = it pleases you / you like

S’il vous plaît = if it pleases you / if you like

S’il vous plaît de faire ainsi = if it pleases you to do so

That’s the grammatical construction; the idiomatic meaning is not “if it pleases you,” but “please”.