Correctly:
1. Purchase a suitable memory card.
2. Open the case.
3. Insert the memory card into the correct slot.
4. Close the case.
The instruction manual is provided by the manufacturer. However, it's a one piece of paper only and it's hard to even get tired reading: https://www.doro.com/globalassets/inriver/resources/qsg_doro_1380_en_a3-a7_v11_1011_1031_20220616.pdf
1. Purchase a suitable memory card.
2. Open the case.
3. Insert the memory card into the correct slot.
4. Close the case.
The instruction manual is provided by the manufacturer. However, it's a one piece of paper only and it's hard to even get tired reading: https://www.doro.com/globalassets/inriver/resources/qsg_doro_1380_en_a3-a7_v11_1011_1031_20220616.pdf