Access S3 bucket after logging on Cognito from other account - amazon-web-services

Question

I have two AWS accounts. The account A has a Cognito identity pool configured with roles for Authenticated and Unauthenticated.
The trusted relationship policy for Authenticated role looks like this:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Federated": "cognito-identity.amazonaws.com"
},
"Action": "sts:AssumeRoleWithWebIdentity",
"Condition": {
"StringEquals": {
"cognito-identity.amazonaws.com:aud": "<identity_pool_id>"
},
"ForAnyValue:StringLike": {
"cognito-identity.amazonaws.com:amr": "authenticated"
}
}
}
]
}
There is also a policy for Authenticated role that looks like this:
{
"Version": "2012-10-17",
"Statement": [
{
"Action": [
"s3:GetObject",
"s3:PutObject",
"s3:DeleteObject"
],
"Resource": [
"arn:aws:s3:::users-pictures/public/*",
"arn:aws:s3:::users-pictures/protected/${cognito-identity.amazonaws.com:sub}/*",
"arn:aws:s3:::users-pictures/private/${cognito-identity.amazonaws.com:sub}/*"
],
"Effect": "Allow"
},
{
"Action": [
"s3:PutObject"
],
"Resource": [
"arn:aws:s3:::users-pictures/uploads/*"
],
"Effect": "Allow"
},
{
"Action": [
"s3:GetObject"
],
"Resource": [
"arn:aws:s3:::users-pictures/protected/*"
],
"Effect": "Allow"
},
{
"Condition": {
"StringLike": {
"s3:prefix": [
"public/",
"public/*",
"protected/",
"protected/*",
"private/${cognito-identity.amazonaws.com:sub}/",
"private/${cognito-identity.amazonaws.com:sub}/*"
]
}
},
"Action": [
"s3:ListBucket"
],
"Resource": [
"arn:aws:s3:::users-pictures"
],
"Effect": "Allow"
}
]
}
On account B I have an application that must authenticate on Cognito from account A, but needs to access a bucket on account B.
This application uses Storage from Amplify.
The bucket structure must be something like this:
users-pictures/private/${cognito-identity.amazonaws.com:sub}/*
When Amplify authenticates on account A and tries to access this bucket on account B, it gets an Access Denied (403).
Probably it's missing some configuration on account A and/or account B.
Could you help me, please?