await redis.rpush("key", "a", "b", "c"); 
const index = await redis.lpos("key", "b");
console.log(index); // 1

​
Arguments

​
key
string
required
The key of the list.
​
element
unknown
required
The element to match.
​
opts
​
rank
number
The rank of the element to match. If specified, the element at the given rank is matched instead of the first element.
​
count
number
The maximum number of elements to match. If specified, an array of elements is returned instead of a single element.
​
maxLen
number
Limit the number of comparisons to perform.

​
Response

The index of the matching element or an array of indexes if opts.count is specified.
await redis.rpush("key", "a", "b", "c"); 
const index = await redis.lpos("key", "b");
console.log(index); // 1