How to use the fastapi.Header function in fastapi

def post_items_all_params_default(
    item_id: str,
    body_item_a: Item,
    body_item_b: Item,
    query_a: int,
    query_b: int,
    coo: str = Cookie(None),
    x_head: int = Header(None),
    x_under: str = Header(None, convert_underscores=False),
):
    return {
        "item_id": item_id,
        "body_item_a": body_item_a,
        "body_item_b": body_item_b,
        "query_a": query_a,
        "query_b": query_b,
        "coo": coo,
        "x_head": x_head,
        "x_under": x_under,
    }

def post_items_all_params_default(
    item_id: str,
    body_item_a: Item,
    body_item_b: Item,
    query_a: int,
    query_b: int,
    coo: str = Cookie(None),
    x_head: int = Header(None),
    x_under: str = Header(None, convert_underscores=False),
):
    return {
        "item_id": item_id,
        "body_item_a": body_item_a,
        "body_item_b": body_item_b,
        "query_a": query_a,
        "query_b": query_b,
        "coo": coo,
        "x_head": x_head,
        "x_under": x_under,
    }

def post_items_all_params(
    item_id: str = Path(...),
    body: Item = Body(...),
    query_a: int = Query(None),
    query_b=Query(None),
    coo: str = Cookie(None),
    x_head: int = Header(None),
    x_under: str = Header(None, convert_underscores=False),
):
    return {
        "item_id": item_id,
        "body": body,
        "query_a": query_a,
        "query_b": query_b,
        "coo": coo,
        "x_head": x_head,
        "x_under": x_under,
    }

def _get_authorization_token(authorization: str = Header(...)):
    token_prefix, token = authorization.split(" ")
    if token_prefix != JWT_TOKEN_PREFIX:
        raise HTTPException(
            status_code=HTTP_403_FORBIDDEN, detail="Invalid authorization type"
        )

    return token

async def list_models(user_agent: str = Header(None)):
	"""
	Lists all available models.
	:param user_agent:
	:return: APIResponse
	"""
	return ApiResponse(data={'models': dl_service.list_models()})

def _get_authorization_token_optional(authorization: str = Header(None)):
    if authorization:
        return _get_authorization_token(authorization)
    return ""

async def verify_token(x_token: str = Header(...)):
    if x_token != "fake-super-secret-token":
        raise HTTPException(status_code=400, detail="X-Token header invalid")

async def get_token_header(x_token: str = Header(...)):
    if x_token != "fake-super-secret-token":
        raise HTTPException(status_code=400, detail="X-Token header invalid")

async def verify_key(x_key: str = Header(...)):
    if x_key != "fake-super-secret-key":
        raise HTTPException(status_code=400, detail="X-Key header invalid")
    return x_key