Update Custom Field

{
  "id": "string",
  "entity_type": "member",
  "key": "string",
  "label": "string",
  "description": "string",
  "field_type": "text",
  "is_required": true,
  "is_member_editable": true,
  "is_member_visible": true,
  "options": [
    null
  ],
  "validation_rules": {},
  "is_active": true,
  "created_at": null,
  "updated_at": null
}

{
  "type": "https://api.members.dev/errors/invalid_credentials",
  "title": "Invalid credentials",
  "status": 401,
  "detail": "Invalid API Key or token.",
  "code": "invalid_credentials"
}

{
  "type": "https://api.members.dev/errors/not_linked_to_tenant",
  "title": "Not linked to tenant",
  "status": 403,
  "detail": "Not linked to this tenant",
  "code": "not_linked_to_tenant"
}

{
  "type": "https://api.members.dev/errors/member_not_found",
  "title": "Member not found",
  "status": 404,
  "detail": "No member exists with the given id in this organization.",
  "code": "member_not_found"
}

{
  "type": "https://api.members.dev/errors/members_context_required",
  "title": "Members context required",
  "status": 422,
  "detail": "This client has multiple organizations. Send the Members-Context header with the organization id (org_…) for this request.",
  "code": "members_context_required"
}

{
  "type": "https://api.members.dev/errors/rate_limit_exceeded",
  "title": "Rate limit exceeded",
  "status": 429,
  "detail": "Rate limit exceeded",
  "code": "rate_limit_exceeded"
}