Ignore blacklist characters and keywords in SSTI exploit payload

Question

I'm exploiting an SSTI (server-side template insertion) vulnerability in a website written in flask-python.

My problem is that payload for RCE is being limited by blacklist.

I tried everything with a document that I found to be hyper-detailed but it didn't help me in this case.

Input:

request.form['name']

Blacklist:

blacklist = ["'", '"', "request", "readlines", "+", "%2b", "%22", '%27', "linecache", "add", "join"]

Handle:

if request.method == "POST":
    for ban in blacklist:
        if ban in request.form['name']:
            return render_template_string('Hacker Alert!!!')
    payload = request.form['name']
    return render_template_string(payload)