Unable to Update Eloquent datatables in Laravel 9

I have 3 Models in My Laravel App like Employee , Salary and Title. Employee Model one to Many Relationship with both Salary and Title Models. Now I need update data using EmployeeController updateEmployee function
EmployeeController

public function updateEmployee(Request $request, $id) {
        $employee = Employee::find($id);
        $title = $employee->titles()->update($request->all);
        $salary = $employee->salaries()->update($request->all);
        if(is_null($employee)) {
            return response()->json(['message' => 'Employee not found'], 404);
        }
        $employee->update($request->all());
       
        return response($employee, 200);
        
    }

and my api route is following

Route::put('updateEmployee/{id}','AppHttpControllersEmployeeController@updateEmployee');

Employee Model

public function titles(): HasMany
    {
        return $this->hasMany(Title::class, 'emp_no');
    }

    public function salaries(): HasMany
    {
        return $this->hasMany(Salary::class, 'emp_no');
    }
}

Salary Model

public function employee(): BelongsTo
    {
        return $this->belongsTo(Employee::class, 'emp_no');
    }

Title Model

public function employee(): BelongsTo
    {
        return $this->belongsTo(Employee::class, 'emp_no');
    }

but when I try update I got following error message

TypeError: IlluminateDatabaseEloquentBuilder::update(): Argument #1 ($values) must be of type array, null given, called in F:2023code2023apivendorlaravelframeworksrcIlluminateSupportTraitsForwardsCalls.php on line 23 in file F:2023code2023apivendorlaravelframeworksrcIlluminateDatabaseEloquentBuilder.php on line 1009

how could I fix this matter?