There are plenty of alternatives for this:

1. Have it done for you. Most photo labs offer this service. The advantage is that professionals do it and they may even clean up dust and spots for you. There is nothing for you to learn or buy, just spend the money for each slide. This is probably the way to go for small quantities in the low hundreds.

2. Buy a slide scanner. This is the highest quality scan and what they actually use in the said photo labs. They are also made for high throughput. One-time cost is the obvious downside but they range from surprisingly cheap to moderately expensive.

3. Buy a slide-attachment for a flatbed scanner. This is another high quality option, slower than the dedicated scanner but can still do 3-6 slides at a time. The resolution depends on your particular scanner but usually very high. Very economical if you already have a compatible scanner. Check with your manufacturer.

4. Buy a slide attachment for your camera. Allows you to scan one slide at a time by taking a picture of it. You need to supply your own uniform backlight too. If you already have a close focusing camera (DSLR with macro lens or equivalent) then this is the cheapest solution. The resulting quality varies greatly and is susceptible to lens defects such as uneven sharpness, distortion, vignetting, aberrations, etc... plus it is effected by the defects of the backlight including color-temperature, color-spectrum and uniformity.