Short answer
Yes — but only if the rule was announced before the lessons began. A rule not announced in advance is not applied retroactively.
Why it is charged
What a coach sells is not the lesson but the hour. When a reserved hour cannot be given to anyone else, the coach bears the cost.
This is not about punishing the client; it makes clear that the hour has a value. An hour with no value attached gets cancelled repeatedly.
The condition: announced in advance
If the rule was not discussed in the first lesson, the first no-show is not charged. A rule applied retroactively damages the relationship itself.
The announcement must be in writing. A rule explained out loud is not remembered when it matters.
The role of records
A lesson marked as a no-show enters the record and shows up in that month's figures. Without records the conversation turns into “how many times did I miss?”.
Absence is data too — something to discuss, not to hide. With a client who keeps missing, the thing to discuss is the schedule, not the fee.