Start with the business problem, react vs livewire not a feature list. What kind of user will use this, how often, and how is the job done today? An estimator who understands the goal will suggest a cheaper route to it; someone handed only a list of screens prices the list as written.
Describe the scope as user stories or scenarios: a walk through each important path. Just as important, state explicitly what is out of scope. An explicit list of exclusions prevents more disagreement later than almost anything else in the document. Also mark which parts are firm and which are still under discussion — estimators price uncertainty, and hiding it helps nobody.
Set out your constraints. This means existing systems the software has to talk to, the data you have and outsource dotnet development where it lives, security and compliance rules, traffic expectations, supported browsers or devices and any technology you are committed to. Where a date is genuinely fixed, say what depends on it: an experienced team is usually able to cut the right scope to protect it, but not if the date is a secret.
Say what the word done means for each item. Acceptance criteria do not require any formal notation: a short list stating what a user should be able to do will do. This single habit compresses acceptance testing by a surprising margin and closes off most late-stage disagreement.
To close, say what you expect back. Require a task-level breakdown, the assumptions behind each number, the main risks and a low number and a high number. Treat a wide range as information, not evasion: it tells you the part of the brief that needs work. From there clarify that area and request a revised number — the second estimate will be far closer to reality.