You don't really ever have to use "shall".
Yours is an example of somewhat legalistic language in which
"shall" is used almost as an imperative, a statement of what is
expected of someone. "will" could have been used, but "shall" is more
emphatic in such statements.
Another case is in asking politely what you are expected to do, in the formula "Shall I ...?" or "Shall we ....?"
"Shall we meet at one o'clock?"
"Shall I begin now?"
Other than in these cases, and perhaps in a very small number of
others which other forum members may add, "will" is almost always used
in preference to "shall", at least in American English.
