You can wear sunscreen in a tanning bed but when you do wear sunscreen in a tanning bed it defeats the purpose of the tanning bed.
Wearing sunscreen in a tanning bed protects your skin but also prevents the UV rays in the tanning bed from tanning your skin.
You can use tanning lotion or tanning oil or even some baby oil to help you develop a good tan when using a tanning bed.
Tanning beds are not safer than the sun.
Tanning beds are actually less safe than the sun and when you tan in a tanning bed you increase your risk of developing skin cancer more when you use a tanning bed.
You can still get skin cancer when tanning in the sun but you're much safer when tanning in the sun than you are when tanning in a tanning bed.
Tanning beds are actually not very safe at all for your health and skin because a tanning bed uses a lot of bad direct UV rays on your skin.
That intense UV ray from the tanning bed can increase your chance of developing skin cancer.
If you want a safer skin tan you should use the sunlight that is natural and outside.