Those look like what we call night light or Christmas light bulbs.
Look around to see if you can find LED bulbs, perhaps in a string, to replace them.
Alternatively, you may have loose wire connections. The only part that is accessible without dismantling the chandelier is the base of the lamp socket.
Using a typing eraser pencil, with the off-white compound as its "lead", polish the bottom of the socket to remove oxidation, then blow out the little pieces of eraser.
There should be no danger, but turn the circuit off first just for general principles.
If loose wires are the problem, you may need to get a qualified, (and trusted), repair person to get into it to check and/or replace the wires. Probably depends on the age of the fixture.
You trying to get old Red lit up...LOL.
I think it is origional to the house..
Could date back to the 20's.
You can't replace those with a string of LEDs.
Well, I guess you could, but only if you don't care what it looks like.
Using a typing eraser pencil, with the off-white compound as its "lead", polish the bottom of the socket to remove oxidation, then blow out the little pieces of eraser.
Always turn off the breaker when attempting this kind of repair.