If you have the necessary AWS credentials:

export AWS_ACCESS_KEY_ID="XXXX"
export AWS_SECRET_ACCESS_KEY="YYYY"

you can install the AWS CLI with:

pip3 install --user awscli

and create an S3 bucket from the command line without using a web browser:

aws s3api create-bucket --acl public-read --bucket my-unique-bucket-name --region eu-central-1 --create-bucket-configuration LocationConstraint=eu-central-1

This will create a publicly readable bucket at http://my-unique-bucket-name.s3.amazonaws.com.

Then you can copy your files with:

aws s3 cp my-file.zip s3://my-unique-bucket-name/subdir/my-file.zip

and share the link http://my-unique-bucket-name.s3.amazonaws.com/subdir/my-file.zip with anyone you want.